{"product_id":"apera-sx751-portable-ph-orp-conductivity-dissolved-oxygen-meter-kit","title":"Apera SX751 Portable pH\/ORP\/Conductivity\/DO Meter Kit","description":"\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;width:100%;max-width:1400px;margin:0 auto;color:#26332C;font-size:1rem;line-height:1.75;\" id=\"bts-sx751-description\"\u003e\n\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(20px,4vw,48px);border:1px solid #B7D0BF;background:#F1F7F3;border-radius:14px;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;flex-wrap:wrap;align-items:center;gap:clamp(24px,4vw,48px);\"\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 340px;min-width:0;\"\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.76rem;font-weight:600;letter-spacing:.12em;text-transform:uppercase;color:#245B45;margin:0 0 12px;\"\u003eAPERA INSTRUMENTS \/ SX751 \/ AI469\u003c\/p\u003e\n\u003ch2 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:clamp(24px,4vw,34px);font-weight:600;line-height:1.2;letter-spacing:-.02em;color:#245B45;margin:0 0 20px;\"\u003eFour measurement methods.\u003cbr\u003eOne portable kit.\u003c\/h2\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eSX751 combines pH, ORP, conductivity and dissolved oxygen testing in a battery-powered carrying-case kit. Connect the appropriate supplied electrode, let the meter recognize its mode, and take one measurement at a time. Conductivity also supports TDS, salinity and resistivity displays; these are related outputs, not additional independent probes. Temperature accompanies supported electrode measurements.\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eChoose AI469 for sequential spot checks with replaceable 201T-S, 301Pt-S, 2301T-S and DO500 electrodes and on-meter recall. The kit includes polarographic DO500, not an optical oxygen sensor. A dedicated 301Pt-S ORP electrode is supplied as well. It is not a simultaneous multichannel logger or a wireless app-based tester.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 340px;min-width:0;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-hero-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-hero-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-hero-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-hero-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"SX751 meter with its supplied probes, shown together for identification. One probe connects at a time; this is not a simultaneous multi-channel arrangement. Screen values are manufacturer examples.\" width=\"1400\" height=\"1400\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:340px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eSX751 meter with its supplied probes, shown together for identification. One probe connects at a time; this is not a simultaneous multi-channel arrangement. Screen values are manufacturer examples.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003cdetails id=\"bts-sx700-kit-guide\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;border:1px solid #FF931A;border-radius:10px;margin:24px 0;background:white;\"\u003e\u003csummary style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;justify-content:space-between;gap:16px;padding:20px;background:#FF931A;color:#172b4d;border-radius:10px;cursor:pointer;line-height:1.5;\"\u003e\u003cspan style=\"flex:1;min-width:0;\"\u003e\u003cspan style=\"display:block;font-size:clamp(17px,2.6vw,21px);font-weight:700;\"\u003eWhich meter kit fits my measurement?\u003c\/span\u003e\u003cspan class=\"bts-sp-when-closed\" style=\"display:block;font-size:.88rem;margin-top:5px;\"\u003eClick or tap to compare all eight measurement configurations\u003c\/span\u003e\u003cspan class=\"bts-sp-when-open\" style=\"font-size:.88rem;\"\u003eClick or tap here to close the guide\u003c\/span\u003e\u003c\/span\u003e\u003cspan class=\"bts-sp-toggle\" aria-hidden=\"true\" style=\"flex:0 0 38px;width:38px;height:38px;display:flex;align-items:center;justify-content:center;border-radius:50%;background:white;font-size:27px;\"\u003e\u003c\/span\u003e\u003c\/summary\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:20px;\"\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eEach card opens that model page. Match the supplied electrode and documented sample method. pH, ORP, conductivity and polarographic dissolved oxygen are different measurements. Match the parameter and meter format before comparing accessories; optional items are not supplied unless the exact kit list says so.\u003c\/p\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;flex-wrap:wrap;gap:14px;\"\u003e\n\u003ca class=\"bts-sx700-kit-link\" data-sx700-kit=\"SX711\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-sx711-portable-ph-mv-meter-kit\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;align-items:flex-start;gap:14px;flex:1 1 300px;min-width:0;padding:18px;border:1px solid #e0e0e0;background:white;border-radius:9px;text-decoration:none;color:#26332C;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx711-hero-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=200\" alt=\"Apera SX711\" width=\"72\" height=\"72\" loading=\"lazy\" style=\"width:72px;height:72px;flex:0 0 72px;object-fit:contain;background:white;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.1rem;font-weight:700;line-height:1.3;margin:0 0 4px;color:#245B45;\"\u003eSX711\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.76rem;margin:0 0 9px;\"\u003eAI460\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;margin:0 0 6px;\"\u003epH and temperature\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;margin:0 0 12px;\"\u003e201T-S pH\/temperature probe; ORP electrode separate.\u003c\/p\u003e\n\u003cspan style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:inline-block;padding:6px 9px;border-radius:5px;background:#FFF0DD;font-size:.85rem;font-weight:700;\"\u003eView SX711 →\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/a\u003e\u003ca class=\"bts-sx700-kit-link\" data-sx700-kit=\"SX721\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-sx721-portable-ph-orp-meter-kit\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;align-items:flex-start;gap:14px;flex:1 1 300px;min-width:0;padding:18px;border:1px solid #e0e0e0;background:white;border-radius:9px;text-decoration:none;color:#26332C;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx721-hero-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=200\" alt=\"Apera SX721\" width=\"72\" height=\"72\" loading=\"lazy\" style=\"width:72px;height:72px;flex:0 0 72px;object-fit:contain;background:white;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.1rem;font-weight:700;line-height:1.3;margin:0 0 4px;color:#245B45;\"\u003eSX721\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.76rem;margin:0 0 9px;\"\u003eAI463\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;margin:0 0 6px;\"\u003epH and ORP kit\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;margin:0 0 12px;\"\u003eSeparate pH and ORP probes; one connection at a time.\u003c\/p\u003e\n\u003cspan style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:inline-block;padding:6px 9px;border-radius:5px;background:#FFF0DD;font-size:.85rem;font-weight:700;\"\u003eView SX721 →\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/a\u003e\u003ca class=\"bts-sx700-kit-link\" data-sx700-kit=\"SX723\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-sx723-portable-ph-conductivity-meter-kit\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;align-items:flex-start;gap:14px;flex:1 1 300px;min-width:0;padding:18px;border:1px solid #e0e0e0;background:white;border-radius:9px;text-decoration:none;color:#26332C;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx723-hero-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=200\" alt=\"Apera SX723\" width=\"72\" height=\"72\" loading=\"lazy\" style=\"width:72px;height:72px;flex:0 0 72px;object-fit:contain;background:white;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.1rem;font-weight:700;line-height:1.3;margin:0 0 4px;color:#245B45;\"\u003eSX723\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.76rem;margin:0 0 9px;\"\u003eAI477\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;margin:0 0 6px;\"\u003epH and conductivity kit\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;margin:0 0 12px;\"\u003eSeparate 201T-S and 2301T-S probes; sequential tests.\u003c\/p\u003e\n\u003cspan style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:inline-block;padding:6px 9px;border-radius:5px;background:#FFF0DD;font-size:.85rem;font-weight:700;\"\u003eView SX723 →\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/a\u003e\u003ca class=\"bts-sx700-kit-link\" data-sx700-kit=\"SX716\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-sx716-portable-polarographic-dissolved-oxygen-meter-kit\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;align-items:flex-start;gap:14px;flex:1 1 300px;min-width:0;padding:18px;border:1px solid #e0e0e0;background:white;border-radius:9px;text-decoration:none;color:#26332C;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx716-hero-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=200\" alt=\"Apera SX716\" width=\"72\" height=\"72\" loading=\"lazy\" style=\"width:72px;height:72px;flex:0 0 72px;object-fit:contain;background:white;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.1rem;font-weight:700;line-height:1.3;margin:0 0 4px;color:#245B45;\"\u003eSX716\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.76rem;margin:0 0 9px;\"\u003eAI461\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;margin:0 0 6px;\"\u003ePolarographic dissolved oxygen\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;margin:0 0 12px;\"\u003eDO500 membrane probe; polarization and movement required.\u003c\/p\u003e\n\u003cspan style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:inline-block;padding:6px 9px;border-radius:5px;background:#FFF0DD;font-size:.85rem;font-weight:700;\"\u003eView SX716 →\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/a\u003e\u003ca class=\"bts-sx700-kit-link\" data-sx700-kit=\"SX725\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-sx725-portable-ph-dissolved-oxygen-meter-kit\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;align-items:flex-start;gap:14px;flex:1 1 300px;min-width:0;padding:18px;border:1px solid #e0e0e0;background:white;border-radius:9px;text-decoration:none;color:#26332C;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx725-hero-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=200\" alt=\"Apera SX725\" width=\"72\" height=\"72\" loading=\"lazy\" style=\"width:72px;height:72px;flex:0 0 72px;object-fit:contain;background:white;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.1rem;font-weight:700;line-height:1.3;margin:0 0 4px;color:#245B45;\"\u003eSX725\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.76rem;margin:0 0 9px;\"\u003eAI465\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;margin:0 0 6px;\"\u003epH and dissolved oxygen\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;margin:0 0 12px;\"\u003eSwap the pH and DO500 probes for sequential tests.\u003c\/p\u003e\n\u003cspan style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:inline-block;padding:6px 9px;border-radius:5px;background:#FFF0DD;font-size:.85rem;font-weight:700;\"\u003eView SX725 →\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/a\u003e\u003ca class=\"bts-sx700-kit-link\" data-sx700-kit=\"SX731\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-sx731-portable-ph-orp-conductivity-meter-kit\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;align-items:flex-start;gap:14px;flex:1 1 300px;min-width:0;padding:18px;border:1px solid #e0e0e0;background:white;border-radius:9px;text-decoration:none;color:#26332C;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-hero-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=200\" alt=\"Apera SX731\" width=\"72\" height=\"72\" loading=\"lazy\" style=\"width:72px;height:72px;flex:0 0 72px;object-fit:contain;background:white;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.1rem;font-weight:700;line-height:1.3;margin:0 0 4px;color:#245B45;\"\u003eSX731\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.76rem;margin:0 0 9px;\"\u003eAI467\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;margin:0 0 6px;\"\u003epH, ORP and conductivity\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;margin:0 0 12px;\"\u003eThree supplied sensor types; not simultaneous acquisition.\u003c\/p\u003e\n\u003cspan style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:inline-block;padding:6px 9px;border-radius:5px;background:#FFF0DD;font-size:.85rem;font-weight:700;\"\u003eView SX731 →\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/a\u003e\u003ca class=\"bts-sx700-kit-link\" data-sx700-kit=\"SX736\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-sx736-portable-ph-conductivity-dissolved-oxygen-meter-kit\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;align-items:flex-start;gap:14px;flex:1 1 300px;min-width:0;padding:18px;border:1px solid #e0e0e0;background:white;border-radius:9px;text-decoration:none;color:#26332C;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-hero-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=200\" alt=\"Apera SX736\" width=\"72\" height=\"72\" loading=\"lazy\" style=\"width:72px;height:72px;flex:0 0 72px;object-fit:contain;background:white;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.1rem;font-weight:700;line-height:1.3;margin:0 0 4px;color:#245B45;\"\u003eSX736\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.76rem;margin:0 0 9px;\"\u003eAI468\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;margin:0 0 6px;\"\u003epH, conductivity and DO\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;margin:0 0 12px;\"\u003eThree probe workflows with distinct storage and calibration.\u003c\/p\u003e\n\u003cspan style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:inline-block;padding:6px 9px;border-radius:5px;background:#FFF0DD;font-size:.85rem;font-weight:700;\"\u003eView SX736 →\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/a\u003e\u003ca class=\"bts-sx700-kit-link\" data-sx700-kit=\"SX751\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-sx751-portable-ph-orp-conductivity-dissolved-oxygen-meter-kit\" aria-current=\"page\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;align-items:flex-start;gap:14px;flex:1 1 300px;min-width:0;padding:18px;border:2px solid #FF931A;background:#FFF9F0;border-radius:9px;text-decoration:none;color:#26332C;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-hero-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=200\" alt=\"Apera SX751\" width=\"72\" height=\"72\" loading=\"lazy\" style=\"width:72px;height:72px;flex:0 0 72px;object-fit:contain;background:white;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.1rem;font-weight:700;line-height:1.3;margin:0 0 4px;color:#245B45;\"\u003eSX751\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.76rem;margin:0 0 9px;\"\u003eAI469\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;margin:0 0 6px;\"\u003epH, ORP, conductivity and DO\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;margin:0 0 12px;\"\u003eFour probe workflows; one input and model-specific records.\u003c\/p\u003e\n\u003cspan style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:inline-block;padding:6px 9px;border-radius:5px;background:#FFF0DD;font-size:.85rem;font-weight:700;\"\u003eCurrent item\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/a\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/details\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003ch2 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:clamp(24px,4vw,34px);font-weight:600;line-height:1.2;letter-spacing:-.02em;color:#245B45;margin:0 0 20px;\"\u003eChoose the electrode for the sample.\u003c\/h2\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;flex-wrap:wrap;gap:16px;\"\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 240px;min-width:0;padding:24px;background:#fff;border:1px solid #DCE6DF;border-radius:10px;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.07rem;font-weight:600;color:#245B45;margin:0 0 12px;\"\u003eRecognize the electrode, then select the display\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eAutomatic recognition selects the measurement family for the connected probe. Use the keypad to choose conductivity, TDS, salinity or resistivity, and the desired resolution or units. This changes the displayed result, not the number of sensors connected. The backlit LCD includes temperature, stability, calibration and memory indicators.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 240px;min-width:0;padding:24px;background:#fff;border:1px solid #DCE6DF;border-radius:10px;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.07rem;font-weight:600;color:#245B45;margin:0 0 12px;\"\u003eKeep instrument range separate from probe suitability\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eThe pH meter spans -2.00 to 19.99 pH, but the current US 201T-S probe page specifies 0 to 13 pH and 0 to 60°C. It is intended for general aqueous samples, not every solution within the meter display range. Older probe instructions show wider limits; use the conservative current probe specification when selecting an application. The current 201T-S listing excludes low-ion water, strong-base samples above pH 12 and highly corrosive liquids. Its probe guide also cautions against frequent testing below pH 2 or above pH 12 and prolonged exposure above 50°C; 0 to 60°C is not a continuous-use guarantee.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 240px;min-width:0;padding:24px;background:#fff;border:1px solid #DCE6DF;border-radius:10px;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.07rem;font-weight:600;color:#245B45;margin:0 0 12px;\"\u003eConductivity with an identifiable cell\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eThe supplied 2301T-S uses a K=1 platinum-black cell and a temperature sensor. Current US documentation rates the probe to 200 mS\/cm; the meter display ends at 199.9 mS\/cm. K=0.1 and K=10 settings accommodate other suitable cells, not extra electrodes in this kit. Verify high-range work against an appropriate standard.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;flex-wrap:wrap;align-items:center;gap:clamp(24px,4vw,48px);\"\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 340px;min-width:0;\"\u003e\n\u003ch2 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:clamp(24px,4vw,34px);font-weight:600;line-height:1.2;letter-spacing:-.02em;color:#245B45;margin:0 0 20px;\"\u003eKnow what this configuration supplies.\u003c\/h2\u003e\n\u003cdiv aria-label=\"Included item table\" role=\"region\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;overflow-x:auto;width:100%;max-width:100%;\" tabindex=\"0\"\u003e\u003ctable style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;width:100%;border-collapse:collapse;font-size:1rem;border:1px solid #e0e0e0;table-layout:fixed;\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth scope=\"col\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;background:#f5f5f5;text-align:left;padding:12px;font-size:1rem;font-weight:700;border:1px solid #e0e0e0;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eIncluded item\u003c\/th\u003e\n\u003cth scope=\"col\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;background:#f5f5f5;text-align:left;padding:12px;font-size:1rem;font-weight:700;border:1px solid #e0e0e0;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eOrder contents\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:32%;font-weight:600;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eSX751 meter\u003c\/td\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eOne handheld meter and one carrying case.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f9f9f9;\"\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:32%;font-weight:600;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003e201T-S pH\/temperature electrode\u003c\/td\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eOne AI1312 electrode with storage vial.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:32%;font-weight:600;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003e2301T-S conductivity\/temperature electrode\u003c\/td\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eOne AI1313 K=1 cell with storage cap.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f9f9f9;\"\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:32%;font-weight:600;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003e301Pt-S ORP electrode\u003c\/td\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eOne AI1315 electrode with storage vial.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:32%;font-weight:600;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eDO500 polarographic electrode\u003c\/td\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eOne AI4110 electrode with calibration\/storage sleeve and working membrane.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f9f9f9;\"\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:32%;font-weight:600;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eDO maintenance supplies\u003c\/td\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eThree spare DO503 membrane caps; one 30 mL DO502 refill; two cathode-polishing papers.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:32%;font-weight:600;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003epH calibration buffers\u003c\/td\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003epH 4.00, 7.00 and 10.01; one 50 mL bottle each.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f9f9f9;\"\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:32%;font-weight:600;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eConductivity standard\u003c\/td\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003e1413 µS\/cm; one 50 mL bottle.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:32%;font-weight:600;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eBatteries and tools\u003c\/td\u003e\n\u003ctd style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:12px;font-size:1rem;line-height:1.6;vertical-align:top;border:1px solid #e0e0e0;width:50%;overflow-wrap:anywhere;min-width:0;\"\u003eTwo AA cells listed as spare; screwdriver and user manual. No additional installed pair promised.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 340px;min-width:0;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-kit-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-kit-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-kit-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-kit-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"Actual SX751 carrying-case kit photograph. Use the itemized kit list for quantities; the battery requirement is two AA cells, not a promise of four supplied batteries.\" width=\"1400\" height=\"1400\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:500px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eActual SX751 carrying-case kit photograph. Use the itemized kit list for quantities; the battery requirement is two AA cells, not a promise of four supplied batteries.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;width:100%;max-width:620px;margin:0 auto;min-width:0;\" data-mfr-feature=\"kit-legend\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-kit-legend-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-kit-legend-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-kit-legend-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-kit-legend-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"Original manufacturer numbered kit graphic. Live legend: 1 meter; 2 DO500; 3 pH probe; 4 ORP probe; 5 conductivity probe; 6 manual; 7 cathode polishing paper; 8 conductivity standard; 9 pH 10.01 buffer; 10 pH 4.00 buffer; 11 pH 7.00 buffer; 12 spare DO membranes; 13 DO refill; 14 two AA batteries; 15 screwdriver. The manual calls the two listed AA cells spare; installed-cell quantity is not independently confirmed.\" width=\"1400\" height=\"1400\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:700px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eOriginal manufacturer numbered kit graphic. Live legend: 1 meter; 2 DO500; 3 pH probe; 4 ORP probe; 5 conductivity probe; 6 manual; 7 cathode polishing paper; 8 conductivity standard; 9 pH 10.01 buffer; 10 pH 4.00 buffer; 11 pH 7.00 buffer; 12 spare DO membranes; 13 DO refill; 14 two AA batteries; 15 screwdriver. The manual calls the two listed AA cells spare; installed-cell quantity is not independently confirmed.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003ch2 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:clamp(24px,4vw,34px);font-weight:600;line-height:1.2;letter-spacing:-.02em;color:#245B45;margin:0 0 20px;\"\u003eMatch the sample and preparation method.\u003c\/h2\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;flex-wrap:wrap;gap:16px;\"\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 240px;min-width:0;padding:24px;background:#fff;border:1px solid #DCE6DF;border-radius:10px;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.07rem;font-weight:600;color:#245B45;margin:0 0 12px;\"\u003eRoutine water and treatment checks\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eCompare compatible water samples using consistent containers, immersion and temperature equilibration. Record the selected parameter and units with every result. Conductivity measures aggregate ionic response; calculated TDS is not a gravimetric solids test, and an ORP or pH reading alone cannot establish drinking-water safety.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 240px;min-width:0;padding:24px;background:#fff;border:1px solid #DCE6DF;border-radius:10px;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.07rem;font-weight:600;color:#245B45;margin:0 0 12px;\"\u003eField rounds with deliberate sample records\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eThe IP57-rated handheld format and carrying case suit spot-check routes where the operator can rinse probes between sites. Use the 400-set memory alongside a sample log. Protect the connector from contamination, keep spare solutions closed, and respect the stated 5 to 35°C instrument working environment.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 240px;min-width:0;padding:24px;background:#fff;border:1px solid #DCE6DF;border-radius:10px;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.07rem;font-weight:600;color:#245B45;margin:0 0 12px;\"\u003eAquatic systems\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eFor ponds, aquaculture or surface-water checks, allow time for DO polarization and sample flow. Do not treat a stationary oxygen probe as an unattended monitor. Use representative sampling and separately document pH and conductivity rather than implying all readings occurred at exactly the same instant.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;flex-wrap:wrap;align-items:center;gap:clamp(24px,4vw,48px);\"\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 340px;min-width:0;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-ph-calibration-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-ph-calibration-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-ph-calibration-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-ph-calibration-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"Original pH calibration photograph with the supplied 201T-S electrode. Select the correct buffer series and wait for stability before accepting each point. Screen values are illustrative.\" width=\"1400\" height=\"1400\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:500px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eOriginal pH calibration photograph with the supplied 201T-S electrode. Select the correct buffer series and wait for stability before accepting each point. Screen values are illustrative.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 340px;min-width:0;\"\u003e\n\u003ch2 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:clamp(24px,4vw,34px);font-weight:600;line-height:1.2;letter-spacing:-.02em;color:#245B45;margin:0 0 20px;\"\u003ePrepare each probe.\u003cbr\u003eCalibrate each method separately.\u003c\/h2\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eAlign the 8-pin plug notch with the single meter socket, push straight in and tighten only the metal locking ring. Do not twist the black rubber cable section. Rinse the selected electrode with distilled or deionized water before testing, remove excess water gently and avoid contaminating fresh standards.\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eFor pH, use the selected USA, NIST or China buffer series and one to three recognized calibration points. The supplied bottles are pH 4.00, 7.00 and 10.01. The manual calls for three-point calibration with a new pH electrode. Match calibration and sample temperatures where practical; automatic temperature compensation corrects electrode response, not every chemical temperature effect.\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eFor conductivity, calibrate in conductivity mode with one recognized standard close to the sample range. The kit supplies 1413 µS\/cm, not every supported standard. Reference temperature choices are 18, 20 or 25°C; the linear coefficient adjusts from 0.00 to 9.99%\/°C, default 2.00. Record settings before comparing batches.\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eFor ORP, connect the 301Pt-S and wait for a stable mV value. The manual requires no ORP calibration; use a suitable 222 mV standard to check performance when needed, observing its temperature-dependent reference value. Do not apply the pH automatic-temperature-compensation claim to ORP or assume a clean pH electrode validates this separate probe.\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eFor DO500, polarize for five minutes after power-on before calibration or testing. Use 30 minutes after replacing a membrane cap or inner solution. Calibrate at saturation in the sleeve with a moist, non-dripping sponge and wait for stability. Temperature and salinity compensation are automatic; barometric pressure is entered manually.\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eRoutine DO calibration is saturation calibration. Optional zero-oxygen calibration follows the exact model manual and requires separately obtained supplies. Sodium sulfite and the 12.88 mS\/cm standard for salinity-sensor recalibration are not listed kit supplies. DO502 is electrode electrolyte, not a calibration standard.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-ec-calibration-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-ec-calibration-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-ec-calibration-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-ec-calibration-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"Original conductivity calibration photograph with the 2301T-S cell. Calibrate in conductivity mode using a suitable recognized standard. The pictured display is an example, not a certified result.\" width=\"1400\" height=\"1400\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:620px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eOriginal conductivity calibration photograph with the 2301T-S cell. Calibrate in conductivity mode using a suitable recognized standard. The pictured display is an example, not a certified result.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-do-calibration-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-do-calibration-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-do-calibration-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-do-calibration-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"Original DO calibration photograph: the DO500 sits in its calibration sleeve, which maintains water-saturated air with a moist sponge. Polarize first and allow stabilization. The screen is an example, not a recorded sample result.\" width=\"1400\" height=\"1400\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:620px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eOriginal DO calibration photograph: the DO500 sits in its calibration sleeve, which maintains water-saturated air with a moist sponge. Polarize first and allow stabilization. The screen is an example, not a recorded sample result.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003ch2 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:clamp(24px,4vw,34px);font-weight:600;line-height:1.2;letter-spacing:-.02em;color:#245B45;margin:0 0 20px;\"\u003eUnderstand the sensing end and connections.\u003c\/h2\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;flex-wrap:wrap;align-items:center;gap:24px;\"\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 300px;min-width:0;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-orp-do-modes-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-orp-do-modes-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-orp-do-modes-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-orp-do-modes-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"Original SX751 ORP and DO configuration graphic. These are alternative single-probe connections, not two simultaneous channels. Display values are examples.\" width=\"1400\" height=\"1400\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:480px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eOriginal SX751 ORP and DO configuration graphic. These are alternative single-probe connections, not two simultaneous channels. Display values are examples.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 300px;min-width:0;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-ph-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=540\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-ph-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-ph-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=540 540w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"201T-S pH\/temperature electrode, AI1312, shown with its 8-pin connector and storage vial. Store in 3M KCl rather than pure water.\" width=\"540\" height=\"750\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:480px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003e201T-S pH\/temperature electrode, AI1312, shown with its 8-pin connector and storage vial. Store in 3M KCl rather than pure water.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 300px;min-width:0;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-ec-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=540\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-ec-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-ec-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=540 540w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"2301T-S conductivity\/temperature electrode, AI1313, K=1, with an 8-pin connector. Its storage cap uses clean distilled or deionized water, not pH storage solution.\" width=\"540\" height=\"750\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:480px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003e2301T-S conductivity\/temperature electrode, AI1313, K=1, with an 8-pin connector. Its storage cap uses clean distilled or deionized water, not pH storage solution.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 300px;min-width:0;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"DO500 polarographic electrode, AI4110, shown with its calibration sleeve and replacement membrane caps. This is a membrane\/electrolyte probe, not an optical DO803 sensor.\" width=\"1400\" height=\"1400\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:480px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eDO500 polarographic electrode, AI4110, shown with its calibration sleeve and replacement membrane caps. This is a membrane\/electrolyte probe, not an optical DO803 sensor.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 300px;min-width:0;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-orp-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=540\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-orp-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-orp-electrode-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=540 540w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"301Pt-S ORP electrode, AI1315. The original photograph shows the 8-pin plug and storage vial. The included ORP probe is separate from the pH electrode.\" width=\"540\" height=\"750\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:480px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003e301Pt-S ORP electrode, AI1315. The original photograph shows the 8-pin plug and storage vial. The included ORP probe is separate from the pH electrode.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;flex-wrap:wrap;align-items:center;gap:clamp(24px,4vw,48px);\"\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 340px;min-width:0;\"\u003e\n\u003ch2 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:clamp(24px,4vw,34px);font-weight:600;line-height:1.2;letter-spacing:-.02em;color:#245B45;margin:0 0 20px;\"\u003eDifferent probes need\u003cbr\u003edifferent storage and maintenance.\u003c\/h2\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eKeep the 201T-S glass bulb hydrated in its 3M KCl storage solution. Do not store a pH electrode in distilled or deionized water. By contrast, the 2301T-S conductivity cap uses clean distilled or deionized water. Rinse between samples and keep the electrical plug dry; never interchange these storage routines.\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eThe low-conductivity nonlinear compensation function is described for readings below 10 µS\/cm. It does not make the supplied pH electrode suitable for ultrapure water. For very low ionic strength pH samples, select an appropriate specialist electrode. Low-range conductivity may require a compatible K=0.1 cell and a controlled flow-cell method.\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eDO500 consumes oxygen during measurement. In still water, the manual requires continuous slow swirling above 5 cm\/s, including while recording. Keep the temperature sensor submerged and the probe at 45 to 75 degrees to the surface. Inspect the membrane and electrolyte for damage or bubbles; use DO503 caps and DO502 refill rather than treating it as a no-refill optical probe.\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eThe current 201T-S listing excludes low-ion water, strong-base samples above pH 12 and highly corrosive liquids. Its probe guide also cautions against frequent testing below pH 2 or above pH 12 and prolonged exposure above 50°C; 0 to 60°C is not a continuous-use guarantee.\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eDO500 is intended for general water solutions, not strong acidic, strong alkaline or organic solutions. Its probe operating temperature is 0 to 50°C, distinct from DO compensation at 0 to 45°C and meter operating conditions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 340px;min-width:0;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-membranes-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-membranes-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-membranes-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-membranes-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"DO503 replacement membrane caps, AI4113, shown as a three-piece service pack. The kit lists three spare caps, in addition to the working cap on the DO500. Avoid touching the sensitive membrane.\" width=\"1400\" height=\"1400\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:500px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eDO503 replacement membrane caps, AI4113, shown as a three-piece service pack. The kit lists three spare caps, in addition to the working cap on the DO500. Avoid touching the sensitive membrane.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-electrolyte-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-electrolyte-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-electrolyte-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-electrolyte-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"DO502 inner solution, AI4112: one 30 mL refill bottle is listed in the kit. Refill without trapped bubbles, then allow 30 minutes of polarization after replacing solution or membrane.\" width=\"1400\" height=\"1400\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:500px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eDO502 inner solution, AI4112: one 30 mL refill bottle is listed in the kit. Refill without trapped bubbles, then allow 30 minutes of polarization after replacing solution or membrane.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-orp-sensing-tip-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=540\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-orp-sensing-tip-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx731-orp-sensing-tip-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=540 540w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"Original 301Pt-S sensing-end close-up from its exact probe page. The protected platinum sensing surface is shown without the storage vial; inspect and clean this electrode separately from the pH probe. No pixels or labels have been invented.\" width=\"540\" height=\"750\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:500px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eOriginal 301Pt-S sensing-end close-up from its exact probe page. The protected platinum sensing surface is shown without the storage vial; inspect and clean this electrode separately from the pH probe. No pixels or labels have been invented.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;margin:0;min-width:0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-sensing-components-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-sensing-components-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-sensing-components-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx736-do-sensing-components-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"Original DO500 annotated component photograph, not a sample reading. Live legend: integrated salinity sensor; temperature sensor; silver anode; gold cathode; replaceable membrane cap. Keep the membrane sound, refill electrolyte when needed and polarize after service.\" width=\"1400\" height=\"1400\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:500px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eOriginal DO500 annotated component photograph, not a sample reading. Live legend: integrated salinity sensor; temperature sensor; silver anode; gold cathode; replaceable membrane cap. Keep the membrane sound, refill electrolyte when needed and polarize after service.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;width:100%;max-width:620px;margin:0 auto;min-width:0;\" data-mfr-feature=\"do-maintenance\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-do-maintenance-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-do-maintenance-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-do-maintenance-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-do-maintenance-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"Original DO500 maintenance schematic. Legend: 1 probe; 2 sleeve cap; 3 sleeve; 4 moist sponge; 5 sleeve bottom lid; 6 temperature sensor; 7 replaceable membrane cap; 8 gold cathode; 9 silver anode; 10 salinity sensor. This is not an optical sensor.\" width=\"1365\" height=\"750\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:500px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eOriginal DO500 maintenance schematic. Legend: 1 probe; 2 sleeve cap; 3 sleeve; 4 moist sponge; 5 sleeve bottom lid; 6 temperature sensor; 7 replaceable membrane cap; 8 gold cathode; 9 silver anode; 10 salinity sensor. This is not an optical sensor.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;flex-wrap:wrap;align-items:center;gap:clamp(24px,4vw,48px);\"\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 340px;min-width:0;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;flex-wrap:wrap;align-items:center;gap:24px;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 300px;min-width:0;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;width:100%;max-width:620px;margin:0 auto;min-width:0;\" data-mfr-feature=\"connector\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-connector-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-connector-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-connector-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-connector-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=1000 1000w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"Original manual connection schematic. Align the notch, push the 8-pin plug straight into the single input, then tighten the metal ring. Never twist the black rubber cable section. Disconnect before changing probes.\" width=\"1365\" height=\"930\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:420px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eOriginal manual connection schematic. Align the notch, push the 8-pin plug straight into the single input, then tighten the metal ring. Never twist the black rubber cable section. Disconnect before changing probes.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\u003c\/div\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 340px;min-width:0;\"\u003e\n\u003ch2 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:clamp(24px,4vw,34px);font-weight:600;line-height:1.2;letter-spacing:-.02em;color:#245B45;margin:0 0 20px;\"\u003eRead the display. Check the measurement mode.\u003c\/h2\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eUse the physical controls for measurement, calibration and the documented record functions. Check units, temperature, calibration indicators and the selected parameter before assigning a result to a sample. Screen values in photographs are illustrative, not sample results. The model-specific record and output workflow is explained below.\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eFollow the exact parameter-specific calibration procedure, using the required standard, solution or calibration atmosphere. Temperature compensation does not make different sample temperatures, preparation methods or chemistry equivalent. Follow the model-specific meter and electrode instructions before extending the method to a new sample.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;display:flex;flex-wrap:wrap;align-items:center;gap:clamp(24px,4vw,48px);\"\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 340px;min-width:0;\"\u003e\n\u003ch2 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:clamp(24px,4vw,34px);font-weight:600;line-height:1.2;letter-spacing:-.02em;color:#245B45;margin:0 0 20px;\"\u003eSave the readings you choose.\u003cbr\u003eKeep sample identity in your own log.\u003c\/h2\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eThe exact SX751 manual documents 400 stored sets. A short memory-key press saves a stabilized result; a long press enters recall. Records contain a serial number, measurement value, unit and temperature. The stated capacity is not a promise of 400 records for every mode or simultaneous complete-parameter datasets.\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eM+ and RM identify saving and recall. The manual does not document a date\/time clock, timed-interval storage, USB export, Bluetooth, browser export or an electronic GLP audit trail. Record sample identity and collection time separately. Deleting memory clears all saved records, so transcribe the required values before using that command.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;flex:1 1 340px;min-width:0;\"\u003e\u003cfigure style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;width:100%;max-width:620px;margin:0 auto;min-width:0;\" data-mfr-feature=\"lcd-legend\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-lcd-legend-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=750\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-lcd-legend-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-lcd-legend-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-lcd-legend-20261016-sx700-eight.webp?v=1792171716\u0026amp;width=750 750w\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" alt=\"Original manual LCD schematic, not a real reading and not simultaneous parameters. Legend: 1 parameter; 2 result; 3 record number and M+\/RM store\/recall status; 4 units; 5 temperature; 6 stability; 7 calibration indicators; 8 low battery. No clock is shown.\" width=\"750\" height=\"588\" loading=\"lazy\" decoding=\"async\" style=\"display:block;width:100%;max-width:500px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\"\u003e\u003cfigcaption style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.86rem;line-height:1.65;color:#5D6C63;margin-top:12px;\"\u003eOriginal manual LCD schematic, not a real reading and not simultaneous parameters. Legend: 1 parameter; 2 result; 3 record number and M+\/RM store\/recall status; 4 units; 5 temperature; 6 stability; 7 calibration indicators; 8 low battery. No clock is shown.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:clamp(28px,5vw,56px) 0;border-bottom:1px solid #B7D0BF;\"\u003e\u003ch2 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:clamp(24px,4vw,34px);font-weight:600;line-height:1.2;letter-spacing:-.02em;color:#245B45;margin:0 0 20px;\"\u003eCompare another measurement format.\u003c\/h2\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eRelated workflow: \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-do8500-10-ft-optical-dissolved-oxygen-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003eApera DO8500 Portable Optical Dissolved Oxygen Meter Kit, 10-ft Cable | AI485\u003c\/a\u003e. The linked optical DO kit has a different sensor technology and maintenance workflow; its probe or cap is not interchangeable with DO500. It is a DO-workflow option, not a replacement for this kit’s other parameters. Compare the exact supplied sensors, measurement parameter, accessories and data features rather than assuming similar model names mean identical kits.\u003c\/p\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:28px 0;line-height:1.15;\" id=\"bts-sx751-faq\"\u003e\u003ch2 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1.1rem;font-weight:600;margin:0 0 16px;\"\u003eSX751 buyer questions\u003c\/h2\u003e\n\u003cdetails style=\"border:1px solid #e0e0e0;border-radius:8px;margin-bottom:10px;background:white;\"\u003e\u003csummary style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:14px 16px;cursor:pointer;font-weight:600;font-size:1rem;line-height:1.15;\"\u003eWhat exactly is included with SX751 \/ AI469?\u003c\/summary\u003e\u003cdiv style=\"padding:0 16px 14px;\"\u003e\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.97rem;line-height:1.6;margin:0;\"\u003eThe supplied electrode models are 201T-S, 301Pt-S, 2301T-S and DO500. All connect through the single 8-pin input. DO500 is polarographic, with replaceable membrane and electrolyte. SX751 includes the separate 301Pt-S for ORP.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #e0e0e0;border-radius:8px;margin-bottom:10px;background:white;\"\u003e\u003csummary style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:14px 16px;cursor:pointer;font-weight:600;font-size:1rem;line-height:1.15;\"\u003eCan it measure every parameter at once?\u003c\/summary\u003e\u003cdiv style=\"padding:0 16px 14px;\"\u003e\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.97rem;line-height:1.6;margin:0;\"\u003eNo. Change the connected electrode for a different measurement family. Recognition selects that probe’s mode; conductivity-derived TDS, salinity and resistivity are display choices, not extra independent sensors. Temperature can accompany supported measurements.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #e0e0e0;border-radius:8px;margin-bottom:10px;background:white;\"\u003e\u003csummary style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:14px 16px;cursor:pointer;font-weight:600;font-size:1rem;line-height:1.15;\"\u003eWhat are the replacement probe part numbers?\u003c\/summary\u003e\u003cdiv style=\"padding:0 16px 14px;\"\u003e\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.97rem;line-height:1.6;margin:0;\"\u003e201T-S is AI1312; 2301T-S is AI1313; 301Pt-S is AI1315; DO500 is AI4110. DO502 refill is AI4112 and DO503 membrane caps are AI4113. Choose the S-version 8-pin connection, not a T-F BNC\/RCA substitute. The optional AI7103 adapter is not supplied.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #e0e0e0;border-radius:8px;margin-bottom:10px;background:white;\"\u003e\u003csummary style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:14px 16px;cursor:pointer;font-weight:600;font-size:1rem;line-height:1.15;\"\u003eDoes the complete kit cover the full displayed pH and EC ranges?\u003c\/summary\u003e\u003cdiv style=\"padding:0 16px 14px;\"\u003e\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.97rem;line-height:1.6;margin:0;\"\u003eNot without considering electrode limits and sample chemistry. The current 201T-S page narrows its range to 0 to 13 pH and 0 to 60°C; older manuals differ. The 2301T-S is rated 0.5 µS\/cm to 200 mS\/cm. Optional cell constants and low-ion compensation do not remove sample-specific limitations. The current 201T-S listing excludes low-ion water, strong-base samples above pH 12 and highly corrosive liquids. Its probe guide also cautions against frequent testing below pH 2 or above pH 12 and prolonged exposure above 50°C; 0 to 60°C is not a continuous-use guarantee.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #e0e0e0;border-radius:8px;margin-bottom:10px;background:white;\"\u003e\u003csummary style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:14px 16px;cursor:pointer;font-weight:600;font-size:1rem;line-height:1.15;\"\u003eHow much memory is available, and can I export it?\u003c\/summary\u003e\u003cdiv style=\"padding:0 16px 14px;\"\u003e\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.97rem;line-height:1.6;margin:0;\"\u003eThe exact manual and specification table state 400 sets, saved and recalled manually, with result, units, temperature and serial number. No timed logging, clock timestamps or electronic export is documented.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #e0e0e0;border-radius:8px;margin-bottom:10px;background:white;\"\u003e\u003csummary style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:14px 16px;cursor:pointer;font-weight:600;font-size:1rem;line-height:1.15;\"\u003eIs the DO probe optical or maintenance-free?\u003c\/summary\u003e\u003cdiv style=\"padding:0 16px 14px;\"\u003e\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.97rem;line-height:1.6;margin:0;\"\u003eNo. DO500 is polarographic. It needs polarization, sound membranes, electrolyte and water movement. It automatically compensates temperature and salinity, but pressure compensation is manual. A 30-second 90% response specification at 25°C is not a guarantee of a finished field result in 30 seconds.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #e0e0e0;border-radius:8px;margin-bottom:10px;background:white;\"\u003e\u003csummary style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:14px 16px;cursor:pointer;font-weight:600;font-size:1rem;line-height:1.15;\"\u003eHow many solution bottles, spare caps and batteries are supplied?\u003c\/summary\u003e\u003cdiv style=\"padding:0 16px 14px;\"\u003e\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.97rem;line-height:1.6;margin:0;\"\u003eThree 50 mL pH buffers and one 50 mL 1413 µS\/cm conductivity standard are listed. The DO kits also list three spare DO503 caps, one 30 mL DO502 refill and two cathode-polishing papers. The manual lists two spare AA cells; it does not independently establish an additional installed pair, so four batteries are not promised.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #e0e0e0;border-radius:8px;margin-bottom:10px;background:white;\"\u003e\u003csummary style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:14px 16px;cursor:pointer;font-weight:600;font-size:1rem;line-height:1.15;\"\u003eWhat warranty applies to the instrument, probes and consumables?\u003c\/summary\u003e\u003cdiv style=\"padding:0 16px 14px;\"\u003e\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:.97rem;line-height:1.6;margin:0;\"\u003eThe current US product page and exact model manual specify three years for the instrument and six months for electrodes, both from delivery. Coverage concerns defects attributable to Apera, with repair or replacement at its option. Exclusions include normal wear, improper use, transport\/storage damage, failure to follow instructions or preventive maintenance, unauthorized changes or repair, and external causes. No separate extended warranty term for membranes or refill solution is stated; routine consumable replacement is not promised.\u003c\/p\u003e\u003c\/div\u003e\u003c\/details\u003e\u003c\/section\u003e\u003csection style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:28px;background:#F1F7F3;border:1px solid #B7D0BF;border-radius:12px;\"\u003e\u003ch2 style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:clamp(24px,4vw,34px);font-weight:600;line-height:1.2;letter-spacing:-.02em;color:#245B45;margin:0 0 20px;\"\u003eConfirm the exact configuration before ordering.\u003c\/h2\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;font-size:1rem;line-height:1.75;margin:0 0 16px;\"\u003eReview SX751 AI469 against the sample, supplied electrode and documented method. Return to the live price and ordering controls when the configuration fits your work.\u003c\/p\u003e\n\u003ca href=\"#\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003eBack to price and ordering ↑\u003c\/a\u003e\u003c\/section\u003e\n\u003c\/div\u003e","brand":"Apera Instruments","offers":[{"title":"Default Title","offer_id":52969306980650,"sku":"BTS-AI469","price":795.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-sx751-hero-20261016-sx700-eight.webp?v=1792171716","url":"https:\/\/bluetigerscientific.com\/products\/apera-sx751-portable-ph-orp-conductivity-dissolved-oxygen-meter-kit","provider":"Blue Tiger Scientific","version":"1.0","type":"link"}