This is a standard solution for PH meter calibration.
pH4.0
Volume: 8.5 fl oz (250
Calibration refers to increased measurement accuracy.
Frequent calibration is recommended for better measurement accuracy. Calibrates the electrode with each standard fluid. Please make sure to calibrate the following situations:
1. When you replace the electrode:
2. Measure chemicals
3.When you need high accuracy.
4.At least once a month