English
Potassium hydrogen phthalate [KHP; pH(S) = 4.005 (25 °C)] is a certified secondary standard reference material used as a calibration buffer standard for pH instruments or pH electrodes.
Certified secondary standard reference material for pH measurement; directly traceable to primary SRM from NIST/PTB pH(S) = 4.00₅ (25°C) Certipur®
