{"product_id":"apera-labsen-551-553-ph-electrode-soil-spear","title":"Apera LabSen 551 \/ 553 Spear pH Electrode for Direct Soil Testing","description":"\u003cdiv id=\"bts-labsen-551-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 551 · 553 \/ AI3106 \/ AI3113\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;\"\u003eDirect soil pH.\u003cbr\u003eNo slurry required.\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 551 and 553 are PVC-body spear pH electrodes for direct soil testing and soil slurry testing. A sturdy S-type spear membrane protects against breakage on insertion, and an open-and-ceramic double junction with polymer electrolyte means no refilling. The 551 has a BNC connector; the 553 adds a built-in temperature sensor with an RCA plug. Both have a 1 m cable.\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 80°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 551 · 553 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-551-main-20261018-mfr.webp?width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-551-main-20261018-mfr.webp?width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-551-main-20261018-mfr.webp?width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-551-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 551 · 553.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003cdetails id=\"bts-labsen-samples-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 small volumes, semi-solids, soil, food and meat. 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: small samples and solids\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 6 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. Published families link to their product pages. Other models are shown for comparison only; confirm the exact connector and host before choosing.\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\u003ca class=\"bts-labsen-family-link\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-241-6-243-6-246-5-ph-electrode-semi-micro-test-tube\" 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 241-6 · 243-6 · 246-5\" 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-241-6-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 241-6 · 243-6 · 246-5\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;\"\u003eAI3103 \/ AI3117 \/ AI3235\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;\"\u003eTest tubes, \u0026gt;0.2 mL\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;\"\u003eØ6 mm sensing tip; down to 60 µL with a semi-micro container.\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 241-6 · 243-6 · 246-5 →\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-241-3-241-3sp-241-180-ph-electrode-micro-volume-nmr\" 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 241-3 · 241-3SP · 241-180\" 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-241-180-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 241-3 · 241-3SP · 241-180\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;\"\u003eAI3104 \/ AI3151 \/ AI3161\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;\"\u003eMicroplates, tubes, NMR\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;\"\u003eØ3 mm tips for samples from 30 µL; protein and NMR versions.\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 241-3 · 241-3SP · 241-180 →\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-251-ph-electrode-semi-solid-spear\" 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 251\" 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-251-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 251\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;\"\u003eAI3105\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;\"\u003eSemi-solids\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;\"\u003eSpear glass membrane with 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 251 →\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/a\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 551 · 553\" 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-551-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 551 · 553\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;\"\u003eAI3106 \/ AI3113\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;\"\u003eSoil and soil slurry\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;\"\u003ePVC spear for direct soil and slurry testing.\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-751-753-ph-electrode-food-spear-titanium\" 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 751 · 753\" 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-751-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 751 · 753\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;\"\u003eAI3157 \/ AI3201\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;\"\u003eCheese, fruit, dough, meat\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;\"\u003eFood-grade titanium body, Ø6 mm spear tip.\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 751 · 753 →\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-761-763-765-ph-electrode-meat-blade-spear-titanium\" 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 761 · 763 · 765\" 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-761-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 761 · 763 · 765\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;\"\u003eAI3159 \/ AI3202 \/ AI3245\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;\"\u003eFresh and frozen meat\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;\"\u003eTitanium blade spear; 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 761 · 763 · 765 →\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 551 · AI3106\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; non-refillable; open + ceramic (double) junction, polymer 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 553 · AI3113\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; non-refillable; open + ceramic (double) junction, polymer electrolyte.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\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;\"\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\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 553 pH electrode\" decoding=\"async\" height=\"719\" loading=\"lazy\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-553-cable-20261018-mfr.webp?width=719\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-553-cable-20261018-mfr.webp?width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-553-cable-20261018-mfr.webp?width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-553-cable-20261018-mfr.webp?width=719 719w\" style=\"display:block;width:100%;max-width:420px;height:auto;object-fit:contain;box-sizing:border-box;margin:0 auto;\" width=\"719\"\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 553.\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;\"\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;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;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;\"\u003eSpear membrane for soil\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;\"\u003eDesigned for direct soil and slurry measurement with fast response and high firmness.\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;\"\u003eOpen \u0026amp; ceramic double junction\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;\"\u003ePolymer electrolyte with a double junction to resist clogging; non-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;\"\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;\"\u003eStable reference potential for field use.\u003c\/p\u003e\n\u003c\/div\u003e\n\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\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 551 feature graphic\" 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-551-junction-graphic-20261018-mfr.webp?width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-551-junction-graphic-20261018-mfr.webp?width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-551-junction-graphic-20261018-mfr.webp?width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-551-junction-graphic-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;\"\u003eFrom Apera’s LabSen product graphics.\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;\"\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 0–80°C; body PVC; glass membrane spear; junction open + ceramic (double); reference electrolyte polymer.\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 551 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-551-dims-20261018-mfr.webp?width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-551-dims-20261018-mfr.webp?width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-551-dims-20261018-mfr.webp?width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-551-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 551 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 551 and 553 are sealed and need no refilling.\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\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;\"\u003eMoisten dry soil before testing (Apera suggests waiting 24 hours after wetting) and make a 10–15 cm pilot hole rather than forcing the probe in.\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;\"\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\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\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-ph8500-sl-portable-soil-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH8500-SL\u003c\/a\u003e (LabSen 553), \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph850-sl-value-portable-soil-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH850-SL\u003c\/a\u003e (LabSen 553).\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-551-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 551 · 553 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 551 \/ 553 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 551 and 553 are PVC-body spear pH electrodes for direct soil testing and soil slurry testing.\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;\"\u003eLabSen 551 (AI3106; BTS-AI3106) is BNC without a temperature sensor. LabSen 553 (AI3113; BTS-AI3113) has BNC\/RCA plugs and a 30 kΩ NTC sensor for compatible Apera meters. The RCA temperature connection is not universally compatible across brands.\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;\"\u003eNo; it is sealed and needs no refilling.\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;\"\u003eHow should I prepare soil for a LabSen 551 or 553?\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 support direct soil and soil-slurry testing. Moisten dry soil; Apera recommends waiting 24 hours after wetting. Make a 10–15 cm pilot hole and insert carefully rather than forcing the glass spear into compact soil.\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 temperature range and cable length do I get?\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 LabSen 551 and 553 are rated pH 0–14 and 0–80°C and have a 1 m cable. The meter and temperature-compensation method must support the actual sample temperature; the electrode rating does not expand host limits.\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 (AI3106 \/ AI3113) 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 551 – BNC","offer_id":53008285696298,"sku":"BTS-AI3106","price":180.0,"currency_code":"USD","in_stock":true},{"title":"LabSen 553 – BNC\/RCA with temp sensor","offer_id":53008285729066,"sku":"BTS-AI3113","price":219.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-551-main-20261018-mfr.webp?v=1792339853","url":"https:\/\/bluetigerscientific.com\/products\/apera-labsen-551-553-ph-electrode-soil-spear","provider":"Blue Tiger Scientific","version":"1.0","type":"link"}