brand	Beifen San Pu	model	PHS-2000
type	Laboratory pH meter	Display mode	Automatic digital display
measuring range	0.0~14.0 PH	accuracy	±0.2 PH
Temperature compensation range	Not exceeding 85% (℃)	supply voltage	4×1.5（V）
working temperature	0~50（℃）

1、 Main technical indicators of PHS-2000 pen type acidity meter:

1. Measurement range: 0.0~14.0 PH
2. Accuracy: ± 0.2 PH
3. Battery: 4 × 1.5V (AG-13 button battery)
4. Battery life: 1000 hours
5. Working temperature: 0~50 ℃ 6. Relative temperature: not exceeding 85%
7. Dimensions: 142 × 29 × 15mm
8. Zero adjustment: adjusted by compensating potentiometer
9. Weight: 65 grams

2、 PHS-2000 pen acidity meter calibration:

1. Immerse the pH electrode in a mixed phosphate standard buffer solution with a pH value of 6.86 (25 ℃) and gently shake.
2. Use a small screwdriver to adjust the potentiometer until the displayed value matches the pH value of the standard buffer solution at ambient temperature.
3. Insert the pH electrode into a standard buffer solution of potassium hydrogen phthalate with a pH of 14.00 or borax with a pH of 9.18.
After about two minutes, the displayed value should be within the allowable error range compared to the pH value of the buffer solution.
Attention: After calibration, it has been used (or placed) for a long time; Electrode usage is particularly frequent; The measurement accuracy requirement is relatively high, and in the above situations, the pH meter must be recalibrated.

3、 Operation steps of PHS-2000 pen type acidity meter:

1. Remove the protective cover
2. First, clean the pH electrode with distilled water and dry it with filter paper.
3. Connect the switch located on the battery compartment
4. Insert the pH into the measured liquid until it reaches the "immersion line". If conditions permit, use the solution to immerse it slightly above the "immersion line".
5. Gently stir the solution and wait for about two minutes, then read the displayed value.
6. After use, clean the electrode, turn off the switch, and put on a protective cover.