Buffer solution pH 4.01 / 25°C / red (citric acid, caustic soda, hydrochloric acid), 1 L, in Dosing bottle

The solution is stabilized against fungal and bacterial attack. We guarantee an error limit of max. +/- 0.02 pH units. The pH value is measured electrometrically in accordance with DIN 19268. The pH meter is calibrated using primary standard buffer solutions in accordance with DIN 19266. The Technolab brand standard buffer solutions are traced back to primary reference materials from the PTB and/or NIST.