HANNA INSTRUMENTS HI70004 pH 4.01 Calibration Solution for Electronic pH Meter

HI70004-U is a premium quality pH 4.01 calibration buffer solution.
Each bag is marked with the batch number and expiry date and is made of a lightweight aluminum block ensuring freshness every time you open it.
Reported values are accurate to +/- 0.01 pH @ 25°C and are traceable to NIST Standard Reference Materials (SRMs).

The lifespan of an electrode varies depending on its use and maintenance.
To optimize the longevity of the electrodes, there are 3 rules to follow:
Rinsing : Rinse with tap water after each measurement.
Storage : Store the electrode upright and always put a few drops of storage solution in the protective cap.