unplug the protective sleeve
If the display of the meter fades, all the 3 batteries have to be replaced. Pull out the battery case and replace the batteries. Pay attention to the polarity of the battery.
The instrument’s PH range must be re-calibrated whenever:
Q1:How often do I need to calibrate?
If the meter is not frequently used, you can calibrate every 2 or 3 month.
Q2:Do I need to calibrate the first I use?
NO.The meter has been calibrated in our factory, you can use directly.
Q3:What is the life of the standard buffer solution?
5 years in powder.