How to calibrate an acidity meter

Normally, the acidity meter should be calibrated once a day to ensure measurement accuracy

① Rinse the electrode with distilled water and absorb the water with filter paper;

② Measure the temperature of the standard solution with a thermometer and adjust the temperature scale of the acidity meter to the measured temperature;

③ When measuring, pull down the small rubber sleeve at the top of the electrode to expose the small hole at the top. Press the PH button to enter the PH measurement mode.

④ First, locate the electrode (adjust the slope to the maximum when positioning the old-fashioned acidity meter), place the electrode in a standard solution with a pH of 6.86, keep the electrode wire still, shake the standard solution bottle to make the solution uniform, adjust the positioning button to 6.86, and then press the confirm button to confirm

⑤ Rinse the electrode with distilled water, absorb the water with filter paper, place the electrode in a standard solution with a pH of 4.0, shake the standard solution bottle to make the solution uniform, adjust the slope key to 4.0, and press the confirm key to confirm.

After adjusting the positioning slope, clean the electrode and absorb 1000 water with filter paper. Then, place it in 6.86 and 4.0 standard solutions to measure whether the values are consistent with the standard solution values. If there is no error in positioning and slope, multiple calibrations can be performed.

After accurate calibration, clean the electrode with distilled water to measure the measured solution. The calibrated acidity meter must not have any further changes in its positioning and slope keys. If there are any changes, it must be recalibrated.