{"product_id":"apera-labsen-211-213-ph-electrode-general-water-tris","title":"Apera LabSen 211 \/ 213 Refillable pH Electrode for General Water Solutions, TRIS Compatible","description":"\u003cdiv id=\"bts-labsen-211-description\" 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;\"\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 \/ LABSEN 211 · 213 \/ AI3101 \/ AI3121\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;\"\u003eThe everyday LabSen.\u003cbr\u003eRefillable, fast and TRIS-ready.\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;\"\u003eLabSen 211 and 213 are Apera’s general-purpose refillable glass pH electrodes for professional lab and field measurement of general water solutions, and they are compatible with TRIS buffers. The 211 is a combination pH electrode with a BNC connector; the 213 adds a built-in temperature sensor with an RCA plug for automatic temperature compensation.\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;\"\u003eIt reads pH 0 to 14 from 0 to 100°C. Choose the version that matches your meter’s connector from the menu above. Apera warrants LabSen electrodes for six months from delivery.\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 alt=\"Apera LabSen 211 · 213 pH electrode\" decoding=\"async\" height=\"1600\" loading=\"lazy\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-211-main-20261018-mfr.webp?width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-211-main-20261018-mfr.webp?width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-211-main-20261018-mfr.webp?width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-211-main-20261018-mfr.webp?width=1000 1000w\" style=\"display:block;width:100%;max-width:420px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\" width=\"1600\"\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;\"\u003eApera LabSen 211 · 213.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003cdetails id=\"bts-labsen-general-selector\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;border:1px solid #FF931A;border-radius:10px;padding:0;margin:24px 0;background:#fff;overflow:visible;\"\u003e\u003csummary aria-label=\"Compare LabSen pH electrodes for general water, wastewater, flat surfaces, pure water and cold samples. Expand or collapse the guide.\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:flex;align-items:center;justify-content:space-between;gap:16px;padding:20px;background:#FF931A;color:#172b4d;cursor:pointer;border-radius:10px;font-weight:600;line-height:1.5;\"\u003e\u003cspan style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:block;flex:1;min-width:0;\"\u003e\u003cspan style=\"display:block;font-size:clamp(17px,2.6vw,21px);font-weight:700;line-height:1.35;\"\u003eChoose your LabSen electrode: water and lab\u003c\/span\u003e\u003cspan style=\"display:block;font-size:.88rem;font-weight:400;line-height:1.55;margin-top:5px;\"\u003e\u003cspan class=\"bts-sp-when-closed\"\u003eClick or tap to compare 7 electrode families\u003c\/span\u003e\u003cspan class=\"bts-sp-when-open\"\u003eCompare the models below - click or tap here to close\u003c\/span\u003e\u003c\/span\u003e\u003c\/span\u003e\u003cspan aria-hidden=\"true\" class=\"bts-sp-toggle\" style=\"display:flex;align-items:center;justify-content:center;flex:0 0 38px;width:38px;height:38px;border:1px solid rgba(23,43,77,.35);border-radius:50%;background:#fff;color:#172b4d;font-size:27px;font-weight:400;line-height:1;\"\u003e\u003c\/span\u003e\u003c\/summary\u003e\u003cp class=\"bts-guide-availability\" style=\"font-family:'Open Sans',sans-serif;font-size:15px;line-height:1.6;color:#26332C;margin:12px 0;\"\u003eOnly published products are linked. Other cards provide model-comparison information and do not indicate current storefront availability.\u003c\/p\u003e\n\u003cdiv class=\"bts-sp-selector-inner\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;padding:20px;\"\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.95rem;font-weight:300;line-height:1.65;margin:0 0 18px;color:#26332C;\"\u003eStart with your sample. Each card opens an electrode family; on that page, pick BNC, BNC\/RCA pH\/temperature or 8-pin to match your meter.\u003c\/p\u003e\n\u003cdiv style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:flex;flex-wrap:wrap;gap:14px;\"\u003e\n\u003cdiv aria-current=\"page\" class=\"bts-labsen-family-link\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:flex;align-items:flex-start;gap:16px;flex:1 1 300px;min-width:0;max-width:100%;padding:18px;border:2px solid #FF931A;background:#FFF9F0;border-radius:9px;text-decoration:none;color:#26332C;transition:box-shadow .15s ease,transform .15s ease,border-color .15s ease;cursor:default;\"\u003e\n\u003cimg alt=\"Apera LabSen 211 · 213\" class=\"bts-sp-model-thumb\" decoding=\"async\" height=\"88\" loading=\"lazy\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-211-main-20261018-mfr.webp?width=200\" style=\"display:block;width:88px;height:88px;flex:0 0 88px;object-fit:contain;background:#fff;border-radius:6px;box-sizing:border-box;\" width=\"88\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:1.1rem;line-height:1.3;font-weight:700;color:#245B45;margin:0 0 3px;\"\u003eLabSen 211 · 213\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.76rem;font-weight:400;line-height:1.5;color:#5D6C63;margin:0 0 9px;\"\u003eAI3101 \/ AI3121\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;color:#26332C;margin:0 0 6px;\"\u003eGeneral water, TRIS buffers\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.86rem;font-weight:300;line-height:1.65;color:#26332C;margin:0 0 12px;\"\u003eRefillable everyday glass electrode; BNC or BNC\/RCA pH\/temp.\u003c\/p\u003e\n\u003cspan class=\"bts-sp-card-cta\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:inline-block;font-size:.85rem;font-weight:700;line-height:1.5;color:#172b4d;background:#FFF0DD;border-radius:5px;padding:6px 9px;background:#F1F7F3;color:#5D6C63;\"\u003eCurrent item\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ca class=\"bts-labsen-family-link\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-221-223-ph-electrode-titration-low-ionic-strength\" rel=\"noopener noreferrer\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:flex;align-items:flex-start;gap:16px;flex:1 1 300px;min-width:0;max-width:100%;padding:18px;border:1px solid #e0e0e0;background:#fff;border-radius:9px;text-decoration:none;color:#26332C;transition:box-shadow .15s ease,transform .15s ease,border-color .15s ease;cursor:pointer;\" target=\"_blank\"\u003e\n\u003cimg alt=\"Apera LabSen 221 · 223\" class=\"bts-sp-model-thumb\" decoding=\"async\" height=\"88\" loading=\"lazy\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-221-main-20261018-mfr.webp?width=200\" style=\"display:block;width:88px;height:88px;flex:0 0 88px;object-fit:contain;background:#fff;border-radius:6px;box-sizing:border-box;\" width=\"88\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:1.1rem;line-height:1.3;font-weight:700;color:#245B45;margin:0 0 3px;\"\u003eLabSen 221 · 223\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.76rem;font-weight:400;line-height:1.5;color:#5D6C63;margin:0 0 9px;\"\u003eAI3102 \/ AI3123\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;color:#26332C;margin:0 0 6px;\"\u003eTitration, low ionic strength\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.86rem;font-weight:300;line-height:1.65;color:#26332C;margin:0 0 12px;\"\u003eMovable sleeve junction: easy to clean, adjustable flow.\u003c\/p\u003e\n\u003cspan class=\"bts-sp-card-cta\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:inline-block;font-size:.85rem;font-weight:700;line-height:1.5;color:#172b4d;background:#FFF0DD;border-radius:5px;padding:6px 9px;\"\u003eView LabSen 221 · 223 →\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\n\u003ca class=\"bts-labsen-family-link\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-231-ph-electrode-wastewater-glass\" rel=\"noopener noreferrer\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:flex;align-items:flex-start;gap:16px;flex:1 1 300px;min-width:0;max-width:100%;padding:18px;border:1px solid #e0e0e0;background:#fff;border-radius:9px;text-decoration:none;color:#26332C;transition:box-shadow .15s ease,transform .15s ease,border-color .15s ease;cursor:pointer;\" target=\"_blank\"\u003e\n\u003cimg alt=\"Apera LabSen 231\" class=\"bts-sp-model-thumb\" decoding=\"async\" height=\"88\" loading=\"lazy\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-231-main-20261018-mfr.webp?width=200\" style=\"display:block;width:88px;height:88px;flex:0 0 88px;object-fit:contain;background:#fff;border-radius:6px;box-sizing:border-box;\" width=\"88\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:1.1rem;line-height:1.3;font-weight:700;color:#245B45;margin:0 0 3px;\"\u003eLabSen 231\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.76rem;font-weight:400;line-height:1.5;color:#5D6C63;margin:0 0 9px;\"\u003eAI3111\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;color:#26332C;margin:0 0 6px;\"\u003eWastewater, suspensions\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.86rem;font-weight:300;line-height:1.65;color:#26332C;margin:0 0 12px;\"\u003eGlass body, open junction and polymer electrolyte.\u003c\/p\u003e\n\u003cspan class=\"bts-sp-card-cta\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:inline-block;font-size:.85rem;font-weight:700;line-height:1.5;color:#172b4d;background:#FFF0DD;border-radius:5px;padding:6px 9px;\"\u003eView LabSen 231 →\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\n\u003ca class=\"bts-labsen-family-link\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-331-333-335-ph-electrode-wastewater-pom\" rel=\"noopener noreferrer\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:flex;align-items:flex-start;gap:16px;flex:1 1 300px;min-width:0;max-width:100%;padding:18px;border:1px solid #e0e0e0;background:#fff;border-radius:9px;text-decoration:none;color:#26332C;transition:box-shadow .15s ease,transform .15s ease,border-color .15s ease;cursor:pointer;\" target=\"_blank\"\u003e\n\u003cimg alt=\"Apera LabSen 331 · 333 · 335\" class=\"bts-sp-model-thumb\" decoding=\"async\" height=\"88\" loading=\"lazy\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-331-main-20261018-mfr.webp?width=200\" style=\"display:block;width:88px;height:88px;flex:0 0 88px;object-fit:contain;background:#fff;border-radius:6px;box-sizing:border-box;\" width=\"88\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:1.1rem;line-height:1.3;font-weight:700;color:#245B45;margin:0 0 3px;\"\u003eLabSen 331 · 333 · 335\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.76rem;font-weight:400;line-height:1.5;color:#5D6C63;margin:0 0 9px;\"\u003eAI3131 \/ AI3133 \/ AI3231\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;color:#26332C;margin:0 0 6px;\"\u003eWastewater, harsh environments\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.86rem;font-weight:300;line-height:1.65;color:#26332C;margin:0 0 12px;\"\u003eCorrosion-resistant POM body, open junction; BNC, BNC\/RCA or 8-pin.\u003c\/p\u003e\n\u003cspan class=\"bts-sp-card-cta\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:inline-block;font-size:.85rem;font-weight:700;line-height:1.5;color:#172b4d;background:#FFF0DD;border-radius:5px;padding:6px 9px;\"\u003eView LabSen 331 · 333 · 335 →\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\n\u003ca class=\"bts-labsen-family-link\" data-labsen-family=\"371\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-371-373-ph-electrode-flat-surface\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:flex;align-items:flex-start;gap:16px;flex:1 1 300px;min-width:0;max-width:100%;padding:18px;border:1px solid #e0e0e0;background:#fff;border-radius:9px;text-decoration:none;color:#26332C;transition:box-shadow .15s ease,transform .15s ease,border-color .15s ease;\"\u003e\u003cimg alt=\"Apera LabSen 371 · 373\" class=\"bts-sp-model-thumb\" decoding=\"async\" height=\"88\" loading=\"lazy\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-371-main-20261018-mfr.webp?width=200\" style=\"display:block;width:88px;height:88px;flex:0 0 88px;object-fit:contain;background:#fff;border-radius:6px;box-sizing:border-box;\" width=\"88\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:1.1rem;line-height:1.3;font-weight:700;color:#245B45;margin:0 0 3px;\"\u003eLabSen 371 · 373\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.76rem;font-weight:400;line-height:1.5;color:#5D6C63;margin:0 0 9px;\"\u003eAI3107 \/ AI3172\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;color:#26332C;margin:0 0 6px;\"\u003eSkin, textiles, paper, leather\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.86rem;font-weight:300;line-height:1.65;color:#26332C;margin:0 0 12px;\"\u003eFlat glass membrane and PTFE ring junction.\u003c\/p\u003e\n\u003cspan class=\"bts-sp-card-cta\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:inline-block;font-size:.85rem;font-weight:700;line-height:1.5;color:#172b4d;background:#FFF0DD;border-radius:5px;padding:6px 9px;\"\u003eView LabSen 371 · 373 →\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/a\u003e\u003ca class=\"bts-labsen-family-link\" data-labsen-family=\"801\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-801-803-805-ph-electrode-pure-water\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:flex;align-items:flex-start;gap:16px;flex:1 1 300px;min-width:0;max-width:100%;padding:18px;border:1px solid #e0e0e0;background:#fff;border-radius:9px;text-decoration:none;color:#26332C;transition:box-shadow .15s ease,transform .15s ease,border-color .15s ease;\"\u003e\u003cimg alt=\"Apera LabSen 801 · 803 · 805\" class=\"bts-sp-model-thumb\" decoding=\"async\" height=\"88\" loading=\"lazy\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-801-main-20261018-mfr.webp?width=200\" style=\"display:block;width:88px;height:88px;flex:0 0 88px;object-fit:contain;background:#fff;border-radius:6px;box-sizing:border-box;\" width=\"88\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:1.1rem;line-height:1.3;font-weight:700;color:#245B45;margin:0 0 3px;\"\u003eLabSen 801 · 803 · 805\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.76rem;font-weight:400;line-height:1.5;color:#5D6C63;margin:0 0 9px;\"\u003eAI3108 \/ AI3137 \/ AI3233\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;color:#26332C;margin:0 0 6px;\"\u003ePure, DI and RO water\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.86rem;font-weight:300;line-height:1.65;color:#26332C;margin:0 0 12px;\"\u003eL-type low-resistance glass (\u0026lt;50 MΩ) for low-ionic water.\u003c\/p\u003e\n\u003cspan class=\"bts-sp-card-cta\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:inline-block;font-size:.85rem;font-weight:700;line-height:1.5;color:#172b4d;background:#FFF0DD;border-radius:5px;padding:6px 9px;\"\u003eView LabSen 801 · 803 · 805 →\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/a\u003e\u003ca class=\"bts-labsen-family-link\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-881-ph-electrode-low-temperature\" rel=\"noopener noreferrer\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:flex;align-items:flex-start;gap:16px;flex:1 1 300px;min-width:0;max-width:100%;padding:18px;border:1px solid #e0e0e0;background:#fff;border-radius:9px;text-decoration:none;color:#26332C;transition:box-shadow .15s ease,transform .15s ease,border-color .15s ease;cursor:pointer;\" target=\"_blank\"\u003e\n\u003cimg alt=\"Apera LabSen 881\" class=\"bts-sp-model-thumb\" decoding=\"async\" height=\"88\" loading=\"lazy\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-881-main-20261018-mfr.webp?width=200\" style=\"display:block;width:88px;height:88px;flex:0 0 88px;object-fit:contain;background:#fff;border-radius:6px;box-sizing:border-box;\" width=\"88\"\u003e\u003cdiv style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;flex:1;min-width:0;\"\u003e\n\u003ch3 style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:1.1rem;line-height:1.3;font-weight:700;color:#245B45;margin:0 0 3px;\"\u003eLabSen 881\u003c\/h3\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.76rem;font-weight:400;line-height:1.5;color:#5D6C63;margin:0 0 9px;\"\u003eAI3149\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.95rem;font-weight:600;line-height:1.5;color:#26332C;margin:0 0 6px;\"\u003eCold samples to −25°C\u003c\/p\u003e\n\u003cp style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;font-size:.86rem;font-weight:300;line-height:1.65;color:#26332C;margin:0 0 12px;\"\u003eL-type conical glass and Protelyte for −25 to 80°C.\u003c\/p\u003e\n\u003cspan class=\"bts-sp-card-cta\" style=\"font-family:'Open Sans',sans-serif;box-sizing:border-box;display:inline-block;font-size:.85rem;font-weight:700;line-height:1.5;color:#172b4d;background:#FFF0DD;border-radius:5px;padding:6px 9px;\"\u003eView LabSen 881 →\u003c\/span\u003e\n\u003c\/div\u003e\n\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;\"\u003ePick the version\u003cbr\u003ethat fits your meter.\u003c\/h2\u003e\n\u003cdiv aria-label=\"Version 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;\"\u003eVersion\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;\"\u003eConnector and build\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;\"\u003eLabSen 211 · AI3101\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;\"\u003eBNC connector, no temperature sensor; refillable; ceramic junction, 3M KCl electrolyte.\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;\"\u003eLabSen 213 · AI3121\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;\"\u003eBNC + RCA plugs, built-in 30 kΩ NTC temperature sensor; refillable; ceramic junction, 3M KCl electrolyte.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\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;\"\u003e\u003cstrong\u003eBNC\u003c\/strong\u003e versions plug into any pH meter with a BNC input. They have no temperature sensor, so pair them with a separate temperature probe such as Apera’s MP500 where compatible with the meter, for automatic temperature compensation; manual temperature entry is an option only if the meter supports it at the sample temperature. Electrode ratings do not extend the meter’s or separate temperature probe’s operating or compensation limits.\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;\"\u003e\u003cstrong\u003eBNC\/RCA\u003c\/strong\u003e versions carry a built-in 30 kΩ NTC temperature sensor on an RCA plug for automatic temperature compensation on Apera meters with BNC and RCA inputs, such as the \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph700-benchtop-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH700\u003c\/a\u003e, \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph850-value-portable-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH850\u003c\/a\u003e, \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph8500-portable-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH8500\u003c\/a\u003e, \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph820-benchtop-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH820\u003c\/a\u003e, \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph910-benchtop-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH910\u003c\/a\u003e and \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph9500-benchtop-ph-meter-kit-with-testbench\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH9500\u003c\/a\u003e. Apera notes they may not work with other brands’ meters because the thermistor might not be compatible.\u003c\/p\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;\"\u003eWhat makes it work.\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;\"\u003eS-type hemispherical membrane\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;\"\u003eLow resistance for fast response and high firmness. Apera says readings fully stabilize in 15–30 seconds and the membrane is 10 times stronger than traditional glass.\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;\"\u003eLong-Life reference system\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;\"\u003eA glass-tube Ag\/AgCl reference with silver wire improves stability and extends service life. Ceramic junction, 3M KCl electrolyte, refillable.\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;\"\u003eBlue gel inner electrolyte\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;\"\u003eApera’s Swiss blue gel keeps air bubbles out of the glass membrane.\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;\"\u003eCheck the specifications.\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;\"\u003eAll versions share: pH range 0–14; temperature range 0–100°C; body lead-free glass; glass membrane S-type, hemispherical; junction ceramic; reference electrolyte 3M KCl.\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 full specification table is in the Product Specifications tab.\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 alt=\"Apera LabSen 213 dimension drawing\" decoding=\"async\" height=\"1600\" loading=\"lazy\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-213-dims-20261018-mfr.webp?width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-213-dims-20261018-mfr.webp?width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-213-dims-20261018-mfr.webp?width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-213-dims-20261018-mfr.webp?width=1000 1000w\" style=\"display:block;width:100%;max-width:460px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\" width=\"1600\"\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;\"\u003eLabSen 213 dimensions, from Apera.\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;\"\u003eStore it wet.\u003cbr\u003eKeep it clean.\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: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:1rem;line-height:1.75;margin:0 0 16px;\"\u003eKeep the tip in its cap with \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-3m-kcl-ph-electrode-storage-soaking-solution\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003e3M KCl storage solution\u003c\/a\u003e whenever it is not measuring.\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;\"\u003eNever store a pH electrode in pure, deionized or distilled water.\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 211 and 213 are refillable: keep the fill hole open while measuring and top up the reference electrolyte when the level drops.\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\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;\"\u003eRinse with distilled or deionized water between samples. For stubborn deposits, use \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-electrode-cleaning-solution-ph-conductivity\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003eApera electrode cleaning solution\u003c\/a\u003e, then recondition and recalibrate.\u003c\/p\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;\"\u003eRelated items.\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;\"\u003eApera ships this electrode in these kits: \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph950-benchtop-ph-meter-kit-with-testbench\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH950\u003c\/a\u003e (LabSen 211), \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph9500-benchtop-ph-meter-kit-with-testbench\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH9500\u003c\/a\u003e (LabSen 211), \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph8500-br-portable-beverage-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH8500-BR\u003c\/a\u003e (LabSen 213), \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph850-br-value-portable-beverage-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH850-BR\u003c\/a\u003e (LabSen 213).\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;\"\u003eCalibrate with fresh \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph-7-00-calibration-buffer-solution\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003epH 7.00\u003c\/a\u003e, \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph-4-00-calibration-buffer-solution\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003epH 4.00\u003c\/a\u003e and \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph-10-01-calibration-buffer-solution\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003epH 10.01\u003c\/a\u003e buffers.\u003c\/p\u003e\u003c\/section\u003e\u003csection id=\"bts-labsen-211-faq\" style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:28px 0;line-height:1.15;\"\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;\"\u003eLabSen 211 · 213 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 is the LabSen 211 \/ 213 made for?\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;\"\u003eLabSen 211 and 213 are Apera’s general-purpose refillable glass pH electrodes for professional lab and field measurement of general water solutions, and they are compatible with TRIS buffers.\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;\"\u003eWhich version do I need?\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;\"\u003eChoose LabSen 211 (AI3101; BTS-AI3101) for BNC pH measurement without a built-in temperature sensor, or LabSen 213 (AI3121; BTS-AI3121) for BNC\/RCA pH and a 30 kΩ NTC sensor on a compatible Apera meter.\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;\"\u003eWill the BNC\/RCA version work on another brand’s meter?\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 pH signal is standard BNC, but Apera notes the temperature thermistor may not be compatible with other brands’ meters. Use it on Apera meters with BNC and RCA inputs.\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 it refillable?\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;\"\u003eYes. Both LabSen 211 and 213 use 3M KCl reference electrolyte. Keep the fill hole open during measurement and refill when the level drops.\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 should I store 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;\"\u003eKeep the tip in its cap with 3M KCl storage solution whenever it is not measuring. Never use pure, deionized or distilled water.\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 pH and temperature range do LabSen 211 and 213 cover?\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;\"\u003eBoth are offered to the current US specifications: pH 0–14 and 0–100°C. Check the meter and temperature-compensation limits separately; a matching connector does not expand them.\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 should I calibrate a new LabSen 211 or 213?\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;\"\u003eUse fresh pH buffers and follow the meter’s calibration procedure. The electrode manuals call for at least a two-point calibration before measuring with a new electrode; rinse between buffers and samples.\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?\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;\"\u003eApera warrants LabSen electrodes against defects in material and workmanship for six months from delivery. Accidental damage, improper use and normal wear are excluded.\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;\"\u003eCheck the version, connector and catalog number (AI3101 \/ AI3121) against your meter and samples, then return to the live price and ordering controls.\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":"LabSen 211 – BNC","offer_id":53008065397034,"sku":"BTS-AI3101","price":125.0,"currency_code":"USD","in_stock":true},{"title":"LabSen 213 – BNC\/RCA with temp sensor","offer_id":53008065429802,"sku":"BTS-AI3121","price":149.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-211-main-20261018-mfr.webp?v=1792339831","url":"https:\/\/bluetigerscientific.com\/products\/apera-labsen-211-213-ph-electrode-general-water-tris","provider":"Blue Tiger Scientific","version":"1.0","type":"link"}