{"product_id":"horiba-reference-electrode-internal-filling-solution","title":"Horiba Reference Electrode Internal Filling Solution","description":"\u003cp\u003eInternal filling solutions for refillable HORIBA reference and combination pH electrodes. These are the electrolyte that fills the reference chamber and completes the electrical circuit through the liquid junction — without it at the correct level and concentration, the electrode cannot produce a stable reading regardless of how well the glass membrane is working.\u003c\/p\u003e\n\n\u003cp\u003eRefillable electrodes are topped up as part of routine maintenance. The level falls through normal outflow at the junction, and the solution should also be replaced periodically because it gradually becomes contaminated by sample carried back through the junction. A slow, drifting or noisy pH reading on a refillable electrode is very often nothing more than low or stale filling solution.\u003c\/p\u003e\n\n\u003ch3\u003eWhat is available\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e310\u003c\/strong\u003e (part no. 3200043622) — internal filling solution.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e300\u003c\/strong\u003e (part no. 3200043640) — reference electrode internal solution for pH electrodes, 250 mL.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eGood practice\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eKeep the filling solution level above the sample level so flow is always outward through the junction — this prevents sample being drawn into the reference chamber\u003c\/li\u003e\n\u003cli\u003eOpen the filling port during measurement and close it for storage\u003c\/li\u003e\n\u003cli\u003eReplace, rather than just top up, the solution if readings remain unstable after cleaning\u003c\/li\u003e\n\u003cli\u003eNever substitute deionized water for filling solution — it destroys the reference potential\u003c\/li\u003e\n\u003cli\u003eMatch the solution to the electrode type; using the wrong concentration shifts the reading\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eApplications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eRoutine maintenance of refillable glass-body pH and reference electrodes\u003c\/li\u003e\n\u003cli\u003eRestoring stability to an electrode with slow or drifting response\u003c\/li\u003e\n\u003cli\u003eRecommissioning an electrode that has been in storage\u003c\/li\u003e\n\u003cli\u003eLaboratory and field pH programs running refillable rather than gel-filled electrodes\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eRelated items\u003c\/h3\u003e\n\u003cp\u003eReference electrodes, refillable combination pH electrodes, electrode cleaning reagents, pH buffers and KCl caps are all stocked — see the \u003ca href=\"https:\/\/envirotechonline.com\/collections\/horiba-parts-accessories\"\u003eHoriba Parts \u0026amp; Accessories\u003c\/a\u003e collection. The 330 gel-type 3.33 mol\/L KCl reference solution is listed with the U-50 Series accessories, and ion-selective electrode filling solutions are listed separately.\u003c\/p\u003e\n\n\u003cp\u003eBrowse all \u003ca href=\"https:\/\/envirotechonline.com\/collections\/horiba\"\u003eHORIBA instruments\u003c\/a\u003e.\u003c\/p\u003e","brand":"Horiba","offers":[{"title":"310 - Internal Filling Solution - 3200043622","offer_id":48226459582654,"sku":"3200043622","price":33.0,"currency_code":"USD","in_stock":true},{"title":"300 - Reference Electrode Internal Solution for pH, 250 mL - 3200043640","offer_id":48226459615422,"sku":"3200043640","price":22.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0592\/9926\/6750\/files\/csm_525-3-KCl_Low-Res_ae9546b931.png?v=1785337371","url":"https:\/\/envirotechonline.com\/products\/horiba-reference-electrode-internal-filling-solution","provider":"EnviroTech Services","version":"1.0","type":"link"}