{"product_id":"apera-labsen-841-843-845-ph-electrode-strong-alkali-high-salinity","title":"Apera LabSen 841 \/ 843 \/ 845 pH Electrode for Strong Alkaline and High-Salinity Solutions","description":"\u003cdiv id=\"bts-labsen-841-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 841 · 843 · 845 \/ AI3145 \/ AI3179 \/ AI3237\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;\"\u003eStrong alkali and brine\u003cbr\u003ewith reduced alkaline error.\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 841, 843 and 845 are made for strong alkaline solutions and high-salinity solutions above 5000 ppm (0.5%). Their robust HA-type glass membrane minimizes alkaline error, and a silver ion trap on the reference resists junction clogging. The 841 (BNC) and 843 (BNC\/RCA with temperature) are refillable with a ceramic junction and 3M KCl; the 845 is the non-refillable 8-pin version with an open junction for PH60 and PH60Z testers fitted with the required 8-pin socket\/adapter.\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;\"\u003eListed operating envelope: pH 0–14 for 841\/843; pH 1–14 for 845 (conservative range); electrode\/sample temperature 0–100°C, subject to host limits. Choose the version that matches your meter’s connection and temperature requirements 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 841 · 843 · 845 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-841-main-20261018-mfr.webp?width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-841-main-20261018-mfr.webp?width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-841-main-20261018-mfr.webp?width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-841-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 841 · 843 · 845.\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\"\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 what makes your sample difficult. 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\" 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: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 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;\"\u003eView LabSen 821 · 823 →\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/a\u003e\u003ca class=\"bts-labsen-family-link\" 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\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 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;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-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-link\" 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-link\" 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-link\" 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-link\" data-bts-unpublished-product=\"10367846875434\" 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 841 · AI3145\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 843 · AI3179\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\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 845 · AI3237\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;\"\u003e8-pin connector, built-in 30 kΩ NTC temperature sensor; non-refillable; open 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 connect to the pH input of BNC pH meters. They have no temperature sensor: use a separate temperature probe supported by the host meter (Apera’s MP500 only where the meter supports it), or manual temperature entry where available.\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\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 \u003cstrong\u003e8-pin\u003c\/strong\u003e version is a pH\/temperature electrode for Apera meters with an 8-pin socket, including the \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-instruments-premium-series-ph60-pocket-ph-tester-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH60\u003c\/a\u003e, \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-zentest-ph60-z-smart-ph-tester-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH60-Z\u003c\/a\u003e, \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/tn420-epa-180-1-compliant-portable-turbidity-meter-precision-testing-for-water-quality-professionals-copy\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH400\u003c\/a\u003e, \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-instruments-ph400s-portable-ph-meter-kit-with-glp-data-management-and-usb-output\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH400S\u003c\/a\u003e and the PC400, PC400S, SX736 and SX751. PH60 and PH60Z require the appropriate installed 8-pin socket\/adapter; this cabled electrode does not replace the native tester probe directly. Confirm the adapter separately; its inclusion is not implied.\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;\"\u003eTemperature figures are electrode\/sample ratings, not a complete-system rating. Use a meter and temperature-compensation method rated for the actual sample temperature; keep the meter body, cable connection and adapter within their own confirmed limits. Connector fit alone does not establish temperature or ATC compatibility.\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 845 pH electrode\" decoding=\"async\" height=\"1563\" loading=\"lazy\" sizes=\"(max-width:600px) calc(100vw - 80px), 560px\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-845-main-20261018-mfr.webp?width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-845-main-20261018-mfr.webp?width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-845-main-20261018-mfr.webp?width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-845-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=\"1563\"\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 845.\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;\"\u003eHA-type glass 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;\"\u003eMinimizes alkaline error in strong alkaline (pH 12–14) and high-salinity samples.\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 reference\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;\"\u003eAdded on top of the Long-Life reference system to further prevent junction clogs.\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;\"\u003eSturdy 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;\"\u003eApera rates it 10 times stronger than traditional glass, with blue gel inner electrolyte.\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 841 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-841-ha-graphic-20261018-mfr.webp?width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-841-ha-graphic-20261018-mfr.webp?width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-841-ha-graphic-20261018-mfr.webp?width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-841-ha-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;\"\u003eOperating envelope: pH 0–14 for 841\/843; pH 1–14 for 845 (conservative range); electrode\/sample temperature 0–100°C, subject to host limits. Common construction: body lead-free glass.\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;\"\u003eJunction: 841 ceramic; 843 ceramic; 845 open.\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;\"\u003eReference electrolyte: 841 3M KCl; 843 3M KCl; 845 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. The 845 is listed here at pH 1–14, the narrower range shared by its standalone page and kit manual. The 0–100°C electrode limit follows the current standalone pages; wider 130°C values in some manuals are not adopted here.\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 841 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-841-dims-20261018-mfr.webp?width=1000\" srcset=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-841-dims-20261018-mfr.webp?width=360 360w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-841-dims-20261018-mfr.webp?width=640 640w, https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-841-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 841 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 841 and 843 are refillable: keep the fill hole open while measuring and top up the reference electrolyte when the level drops.\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 845 is sealed and needs 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;\"\u003eApera’s manual advises avoiding strong acids and dehydrating media such as absolute ethanol or concentrated sulfuric acid; if exposure is unavoidable, keep immersion short and clean the electrode carefully afterward.\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-ph850-sa-value-portable-strong-alkali-high-salinity-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH850-SA\u003c\/a\u003e (LabSen 843), \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph8500-sa-portable-strong-alkali-high-salinity-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH8500-SA\u003c\/a\u003e (LabSen 843), \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph700-sa-benchtop-ph-meter-kit\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH700-SA\u003c\/a\u003e (LabSen 843), \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-instruments-ph60-sa-handheld-ph-meter-tester-kit-for-strong-alkaline-or-high-salinity-water-solutions-with-labsen-845-atc-ph-electrode\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH60-SA\u003c\/a\u003e (LabSen 845), \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-instruments-ph60z-sa-smart-ph-tester-kit-for-strong-alkaline-and-high-salinity-samples-with-labsen-845-electrode\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003ePH60Z-SA\u003c\/a\u003e (LabSen 845).\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, or \u003ca href=\"https:\/\/bluetigerscientific.com\/products\/apera-ph-12-45-calibration-buffer-solution\" style=\"color:#245B45;text-decoration:underline;font-weight:600;\"\u003epH 12.45\u003c\/a\u003e for the alkaline side.\u003c\/p\u003e\u003c\/section\u003e\u003csection id=\"bts-labsen-841-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 841 · 843 · 845 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 841 \/ 843 \/ 845 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 841, 843 and 845 are made for strong alkaline solutions and high-salinity solutions above 5000 ppm (0.5%).\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;\"\u003e841 has BNC for pH only; 843 adds an RCA-connected 30 kΩ NTC temperature sensor for a compatible Apera meter; 845 uses Apera’s 8-pin connection. PH60\/PH60Z need the appropriate installed 8-pin socket\/adapter, not a direct native-probe swap. Check host compatibility and adapter supply before ordering.\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 uses BNC, but the built-in 30 kΩ NTC temperature sensor is not universally compatible. Apera lists meters with matching BNC\/RCA inputs; verify the meter’s thermistor support and temperature range before relying on ATC.\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;\"\u003eThe 841 and 843 are refillable; the 845 is sealed.\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 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\u003cdetails style=\"border:1px solid #e0e0e0;border-radius:8px;margin-bottom:10px;background:white;\"\u003e\u003csummary style=\"font-family:'Open Sans',sans-serif;font-weight:300;box-sizing:border-box;padding:14px 16px;cursor:pointer;font-weight:600;font-size:1rem;line-height:1.15;\"\u003eDoes the HA membrane eliminate alkaline error?\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. The HA membrane minimizes alkaline error in strong alkaline and high-salinity samples; it is not a zero-error guarantee. Choose the 841\/843 refillable ceramic-junction design or 845 sealed open-junction design to suit your meter and maintenance needs.\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 limits should I use?\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;\"\u003eThis listing uses pH 0–14 for 841\/843 and the conservative pH 1–14 for 845. All three retain the current standalone-page electrode limit of 0–100°C; wider manual temperatures are not adopted. The meter’s temperature\/ATC and connector limits still apply; a PH60’s manual specifies ATC at 0–50°C.\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 (AI3145 \/ AI3179 \/ AI3237) 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 841 – BNC","offer_id":53008175497514,"sku":"BTS-AI3145","price":159.0,"currency_code":"USD","in_stock":true},{"title":"LabSen 843 – BNC\/RCA with temp sensor","offer_id":53008175530282,"sku":"BTS-AI3179","price":195.0,"currency_code":"USD","in_stock":true},{"title":"LabSen 845 – 8-pin for PH60\/PH60Z","offer_id":53008175563050,"sku":"BTS-AI3237","price":166.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/apera-labsen-841-main-20261018-mfr.webp?v=1792339874","url":"https:\/\/bluetigerscientific.com\/products\/apera-labsen-841-843-845-ph-electrode-strong-alkali-high-salinity","provider":"Blue Tiger Scientific","version":"1.0","type":"link"}