The new digital tester shouldn't need to be adjusted. When you turn on the tester , you may find the measured value is not accurate and unstable, it's normal phenomenon. Put the digital tester in the liquid that you want to test about 1 minute and you can read the PH. If you find it not accurate, use the Calibration Adjustment Screwdriver (including) to adjust the adjustment trimmer.
This digital pen style pH meter is an ideal instrument for aquarium, fishing industry, swimming pool,
school laboratory, food & beverage etc. Very excellent, accurate and durable.
Features & details:
Measuring pH Range: 0.0 - 14.0 pH
Resolution: 0.1 pH
Accuracy: ±0.1 pH (20°C), ±0.2 pH
Operating Temperature: 0 - 50°C (32 - 122°F)
Calibration: Manual,1 point (not including calibration buffer solution)
Item Net Weight: Approx. 57g (after installed batteries)
Dimensions: 152 x 29 x 20mm (5.984 x 1.142 x 0.591 inch)
1 x Digital pH meter
1 x Calibration Adjustment Screwdriver
3 x Batteries Included in pH Meter
1 x User instruction (English)