{"product_id":"apera-labsen-821-823-ph-electrode-protein-dairy-biotech","title":"Apera LabSen 821 \/ 823 Refillable pH Electrode for Biotech, Pharma, Dairy and Protein-Containing Liquids","description":"\u003cdiv id=\"bts-labsen-821-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 821 · 823 \/ AI3141 \/ AI3153\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;\"\u003eProteins clog ordinary junctions.\u003cbr\u003eProtelyte doesn’t.\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 821 and 823 are refillable glass pH electrodes for biotechnology, pharmaceuticals and food: protein-containing liquids, biological fluids, enzyme solutions, TRIS buffers, milk, yogurt, jam and sauce. Their Protelyte electrolyte and triple ceramic junction are built for samples that clog a standard KCl reference. The 821 has a BNC connector; the 823 adds a built-in temperature sensor with an RCA plug.\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 −5 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 821 · 823 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-821-main-20261018-mfr.webp?width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-821-main-20261018-mfr.webp?width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-821-main-20261018-mfr.webp?width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-821-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 821 · 823.\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003cdetails id=\"bts-labsen-chemistry-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 proteins, HF and strong acids, strong alkalis, viscous samples, high temperature and organic solvents. 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: demanding chemistry\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 8 electrode families\u003c\/span\u003e\u003cspan class=\"bts-sp-when-open\"\u003eChoose an item 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\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 what makes your sample difficult. Each card opens an electrode family; on that page, pick the connector that matches 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\u003ca aria-current=\"page\" class=\"bts-labsen-family-link\" data-labsen-family=\"821\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-821-823-ph-electrode-protein-dairy-biotech\" 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;\"\u003e\u003cimg alt=\"Apera LabSen 821 · 823\" 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-821-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 821 · 823\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;\"\u003eAI3141 \/ AI3153\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;\"\u003eProteins, dairy, biotech\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;\"\u003eProtelyte electrolyte and triple ceramic 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;\"\u003eCurrent item\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/a\u003e\u003ca class=\"bts-labsen-family-comparison\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-831-833-835-ph-electrode-hf-strong-acid\" 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 831 · 833 · 835\" 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-835-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 831 · 833 · 835\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;\"\u003eAI3109 \/ AI3177 \/ AI3239\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;\"\u003eStrong acids, HF\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;\"\u003eHF-resistant glass; spot measurements below 0.1 mol\/L HF.\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 831 · 833 · 835 →\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\n\u003ca class=\"bts-labsen-family-comparison\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-841-843-845-ph-electrode-strong-alkali-high-salinity\" 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 841 · 843 · 845\" 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-841-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 841 · 843 · 845\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;\"\u003eAI3145 \/ AI3179 \/ AI3237\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;\"\u003epH 12–14, salinity \u0026gt;0.5%\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;\"\u003eHA glass minimizes alkaline error; silver ion trap.\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 841 · 843 · 845 →\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\n\u003ca class=\"bts-labsen-family-comparison\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-851-1-ph-electrode-viscous-protelyte\" 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 851-1\" 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-851-1-tip-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 851-1\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;\"\u003eAI3110\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;\"\u003eSkincare, cosmetics, coatings\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;\"\u003eConical membrane with Protelyte and triple ceramic 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 851-1 →\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\n\u003ca class=\"bts-labsen-family-comparison\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-853-s-ph-electrode-viscous-pre-pressurized\" 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 853-S\" 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-853-s-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 853-S\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;\"\u003eAI3165\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;\"\u003eCoatings, syrups, resin, glue\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;\"\u003ePre-pressurized gel KCl with low-impedance S membrane.\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 853-S →\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\n\u003ca class=\"bts-labsen-family-comparison\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-851-h-853-h-855-ph-electrode-viscous-alkaline-pre-pressurized\" 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 851-H · 853-H · 855\" 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-851-h-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 851-H · 853-H · 855\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;\"\u003eAI3168 \/ AI3180 \/ AI3243\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;\"\u003eViscous, alkaline or salty\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;\"\u003ePre-pressurized gel KCl and HA glass; 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 851-H · 853-H · 855 →\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\n\u003ca class=\"bts-labsen-family-comparison\" href=\"https:\/\/bluetigerscientific.com\/products\/apera-labsen-861-863-865-ph-electrode-high-temperature-caustic\" 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 861 · 863 · 865\" 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-861-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 861 · 863 · 865\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;\"\u003eAI3167 \/ AI3176 \/ AI3241\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;\"\u003eHot, caustic, electroplating\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;\"\u003ePHY glass and PTFE ring junction, rated to 130°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 861 · 863 · 865 →\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\n\u003cdiv class=\"bts-labsen-family-comparison\" data-bts-held-family=\"871\" data-bts-unpublished-product=\"10367846875434\" role=\"group\" 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:default;\"\u003e\n\u003cimg alt=\"Apera LabSen 871\" 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-871-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 871\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;\"\u003eAI3147\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;\"\u003eOrganic solvents\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;\"\u003ePHY glass, double junction with 1M LiCl outer bridge.\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;\"\u003eModel comparison\u003c\/span\u003e\n\u003c\/div\u003e\n\u003c\/div\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 821 · AI3141\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 × 3 junction, Protelyte 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 823 · AI3153\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 × 3 junction, Protelyte 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 for automatic temperature compensation, or enter the temperature 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;\"\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;\"\u003eProtelyte 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;\"\u003eDesigned for biotechnology, pharmaceuticals and protein-containing liquids. Apera describes it as tasteless, odorless and microorganism-safe, compliant with EC Regulation 1935\/2004.\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;\"\u003eSilver ion trap + triple ceramic\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;\"\u003eReduces junction clogging from proteins and sulfites.\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;\"\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;\"\u003eFast response and high firmness, with blue gel inner electrolyte.\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 −5–100°C; body lead-free glass; glass membrane S-type, hemispherical; junction ceramic × 3; reference electrolyte Protelyte.\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 821 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-821-dims-20261018-mfr.webp?width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-821-dims-20261018-mfr.webp?width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-821-dims-20261018-mfr.webp?width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-821-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 821 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 electrode wet in \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-protelyte-ph-electrode-storage-solution\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003eApera Protelyte storage solution\u003c\/a\u003e when it is not in use.\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 821 and 823 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-ph700-bc-benchtop-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH700-BC\u003c\/a\u003e (LabSen 823), \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph8500-dp-portable-liquid-food-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH8500-DP\u003c\/a\u003e (LabSen 823), \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph850-dp-value-portable-liquid-food-protein-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH850-DP\u003c\/a\u003e (LabSen 823).\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-821-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 821 · 823 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 821 \/ 823 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 821 and 823 are refillable glass pH electrodes for biotechnology, pharmaceuticals and food: protein-containing liquids, biological fluids, enzyme solutions, TRIS buffers, milk, yogurt, jam and sauce.\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;\"\u003eMatch the connector to your meter: BNC for any BNC pH meter (no temperature sensor), BNC\/RCA for Apera meters with BNC and RCA inputs (built-in temperature sensor),.\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.\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 electrode wet in Apera Protelyte storage solution when it is not in use. 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 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 (AI3141 \/ AI3153) 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 821 – BNC","offer_id":53008517628202,"sku":"BTS-AI3141","price":149.0,"currency_code":"USD","in_stock":true},{"title":"LabSen 823 – BNC\/RCA with temp sensor","offer_id":53008517660970,"sku":"BTS-AI3153","price":195.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-821-main-20261018-mfr.webp?v=1792339875","url":"https:\/\/bluetigerscientific.com\/products\/apera-labsen-821-823-ph-electrode-protein-dairy-biotech","provider":"Blue Tiger Scientific","version":"1.0","type":"link"}