Metrohm, 6.230.7200, Buffer solution pH 4.00 (30 x 30 mL)

Metrohm pH 4.00 buffer solution supplies a ready-to-use, colorless calibration standard with the stated pH value at 25 °C. The package contains thirty individually portioned 30 mL single-use sachets, enabling laboratories to open a fresh volume for each calibration session instead of repeatedly dipping electrodes into a large stock bottle. This packaging helps limit carryover, evaporative changes and contamination during routine electrochemical measurements. The acidic-range buffer is appropriate for low-pH calibration and checks for acidic aqueous samples, such as beverages, process solutions and laboratory acid–base assays. It supports compatible pH measurement systems and multibuffer calibration procedures when used with other reference points. Temperature matters when assigning pH values; this label refers specifically to 25 °C, not to an invariant value at all temperatures.