{"product_id":"buffer-solution-ph-4-red-1-pint-1-gallon","title":"Buffer Solution pH 4, Red","description":"\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhat it is.\u003c\/strong\u003e This pH 4 buffer solution is a color-coded red pH standard used to calibrate pH meters and electrodes in the acidic range. It is offered in 1-pint and 1-gallon sizes.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhy calibrate at pH 4.\u003c\/strong\u003e Two-point calibration sets both the electrode's zero point and its slope. pH 7 sets the zero point, and pH 4 sets the slope for acidic measurements. Bracketing acidic samples between pH 4 and pH 7 lets the meter interpolate readings rather than extrapolate them, improving accuracy across the acidic range.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHow a buffer holds its pH.\u003c\/strong\u003e A buffer contains a weak acid and its conjugate base, or a weak base and its conjugate acid, in balanced amounts. When small amounts of acid or base enter the solution, one partner neutralizes them, so the pH barely moves. That resistance to change is what makes a buffer a reliable reference point for calibration, unlike plain water.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhy color-coded red.\u003c\/strong\u003e Red is the widely used color for pH 4 buffers, alongside yellow for pH 7 and blue for pH 10. Color coding lets technicians grab the right buffer at a glance and reduces mix-ups during multi-point calibration.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe most stable calibration point.\u003c\/strong\u003e Acidic buffers are less affected by carbon dioxide from the air than alkaline buffers, so an opened pH 4 buffer typically stays within specification longer than pH 10. Good practice still applies: keep the container closed, pour only what you need, and discard used buffer.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature matters.\u003c\/strong\u003e Buffer pH shifts slightly with temperature. Calibrate at the same temperature as your samples, use a meter with automatic temperature compensation, and apply any temperature-correction values supplied with the buffer for the most accurate readings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTwo sizes for different workloads.\u003c\/strong\u003e The 1 pint size (ZB1628-16.1) suits benches that calibrate a few times a week. The 1 gallon size (ZB1628-128) suits QC and production labs that calibrate several meters daily and want a lower cost per calibration.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCalibration best practice.\u003c\/strong\u003e Rinse the electrode with deionized water, blot it gently between buffers, immerse it in a fresh buffer in a clean beaker, stir gently, and wait for a stable reading before accepting each point. Calibrate before each day's measurements, or more often as the method requires, and record the meter-reported slope to track electrode health.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhere it is used.\u003c\/strong\u003e Use pH 4 buffer to calibrate benchtop, portable, and in-line pH meters in food and beverage, pharmaceutical, environmental, plating, and teaching labs, wherever samples are acidic. It pairs with Lab Pro's Buffer Solution pH 7, Yellow, and Buffer Solution pH 10, Blue for full three-point calibration, and with Buffer Solution pH 2 for strongly acidic samples.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003ctable style=\"width:100%; border-collapse:collapse; border:1px solid #cfcfcf; margin-bottom:28px;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eProduct\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003epH 4 buffer solution, color-coded red\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eNominal pH\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003e4 at 25 °C\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eColor Code\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003eRed\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eUse\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003epH meter and electrode calibration, slope setting for acidic samples\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003ePackage Sizes\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003e1 pint; 1 gallon\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch4\u003eAvailable Variants\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eZB1628-16.1:\u003c\/strong\u003e 1 pint for occasional calibration.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eZB1628-128:\u003c\/strong\u003e 1 gallon for labs that calibrate several meters daily.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eApplications \/ Common Uses\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003epH meter calibration:\u003c\/strong\u003e Sets the electrode slope for acidic measurements alongside pH 7.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSlope verification:\u003c\/strong\u003e Checks electrode response after cleaning or reconditioning.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDaily QC checks:\u003c\/strong\u003e Confirms meter accuracy before acidic sample runs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFood and beverage testing:\u003c\/strong\u003e Brackets acidic products such as juices and fermented foods.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTeaching labs:\u003c\/strong\u003e Demonstrates buffer behavior and meter calibration.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eStorage, Handling \u0026amp; Shipping\u003c\/h4\u003e\n\u003cp\u003eStore pH 4 buffer tightly closed at room temperature, protected from light and freezing. Keep it free of contamination by pouring portions into a clean beaker for each calibration and never dipping an electrode into the stock.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eStorage temperature:\u003c\/strong\u003e Store at room temperature and protect from light and freezing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eContamination control:\u003c\/strong\u003e Pour the amount needed into a clean beaker; never return used buffer to stock or dip an electrode into the stock container.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShelf life:\u003c\/strong\u003e Use before the expiration date on the label; once opened, use within the period stated on the certificate or label.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRinsing:\u003c\/strong\u003e Rinse electrodes with deionized water between buffers to prevent carryover.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eRelated Categories \u0026amp; Services\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eShop \u003ca href=\"https:\/\/labproinc.com\/collections\/buffers-by-lab-pro\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eBuffers by Lab Pro\u003c\/a\u003e for related products in this category.\u003c\/li\u003e\n\u003cli\u003eExplore \u003ca href=\"https:\/\/labproinc.com\/collections\/ph-buffers-test-kits\" target=\"_blank\" rel=\"noopener noreferrer\"\u003ePH Buffers \u0026amp; Test Kits\u003c\/a\u003e and \u003ca href=\"https:\/\/labproinc.com\/pages\/buffers-standards-solutions\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eBuffers, Standards \u0026amp; Solutions\u003c\/a\u003e.\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/labproinc.com\/pages\/be-a-lab-pro-vmi-program\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eVendor Managed Inventory (VMI) Program\u003c\/a\u003e: Lab Pro can stock, track, and replenish this item on site so it never runs out. Contact info@labproinc.com or 888-452-2776 to set up a VMI assessment.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eRelated Articles\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/labproinc.com\/blogs\/chemicals-and-solvents\/mastering-the-art-of-ph-control-unveiling-the-science-behind-buffer-ph4\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eMastering the Art of pH Control: Unveiling the Science Behind Buffer pH4\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/labproinc.com\/blogs\/chemicals-and-solvents\/which-ph-buffer-solution-should-i-use\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eWhich pH Buffer Solution Should I Use When Calibrating?\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/labproinc.com\/blogs\/lab-equipment-calibration\/the-role-of-calibration-in-quality-control-maintaining-consistency-and-compliance\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eThe Role of Calibration in Quality Control: Maintaining Consistency and Compliance\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Lab Pro Inc","offers":[{"title":"1 Pint","offer_id":67674912751765,"sku":"ZB1628-16.1","price":17.37,"currency_code":"USD","in_stock":true},{"title":"1 Gallon","offer_id":47266345091221,"sku":"ZB1628-128","price":56.72,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0757\/2327\/6437\/files\/MainImage_6394f5db-82ad-4032-9a98-f86cfa8b55a3.png?v=1791285481","url":"https:\/\/checkout.labproinc.com\/products\/buffer-solution-ph-4-red-1-pint-1-gallon","provider":"Lab Pro Inc Plus","version":"1.0","type":"link"}