Calibration of the pH meter
1, the calibration powder with 250ml of distilled water or pure water to open. Dip the pH electrode into a mixed phosphate standard buffer at pH 6.86 and shake gently.
2, push the CAL button,it will auto calibration until the displayed value and the standard buffer solution at pH 6.9 consistent with the ambient temperature.
3, the same as above, the electrode was inserted into pH4.01 Phosphorous stupid acid potassium bicarbonate standard buffer solution.
4, about two minutes or so. The displayed value should be within the error tolerance compared to the pH value of the buffer solution.