{"product_id":"ph4-calibration-solution-16-oz","title":"PH4 Calibration Solution, 16 oz","description":"\u003cp\u003eHanna's buffer solutions are made from established formulas and are standardized with a pH meter calibrated to NBS\/NIST primary standard buffer solutions. The 20 ml sachets are ideal for infrequent calibrations while for heavy-duty applications, you can choose from the popular 230 ml, 1 liter, or 1 gallon containers. Now the pH 4 buffers carry lot # and expiry date as well as pH\/C chart on every bottle. HI 7004L\/C and HI 8004L\/C are also supplied with an analysis certificate.\u003c\/p\u003e  \u003cp\u003eHanna pH 4 buffers contain potassium hydrogen phthalate. They are standardized using a pH meter calibrated by primary standard buffer solutions (NIST 186 Ie, NIST 186 IIe and NIST 185g S.R.M.). The pH value is certified traceable to NIST 185g S.R.M.\u003c\/p\u003e","brand":"Hydrofarm","offers":[{"title":"Default Title","offer_id":32109290913877,"sku":"HI7004L","price":19.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/3099\/1090\/products\/HI7004L_1.jpg?v=1588094302","url":"https:\/\/growmasters.com\/products\/ph4-calibration-solution-16-oz","provider":"Grow Masters","version":"1.0","type":"link"}