11 Precautions for Using a pH Meter
1. Open the back cover and insert a battery.
2. Install the composite glass electrode Note:
(1) The lower end of the composite electrode is a fragile glass bulb, so be careful when using and storing it to prevent it from colliding with other objects.
(2) There is a KCl saturated solution in the composite electrode as a conductive medium. If the result of drying up is inaccurate, you must observe whether there is any liquid at any time. If there is a small amount left, go to the laboratory for perfusion.
(3) No pollution, including water droplets, is allowed at the instrument interface of the composite electrode.
(4) The composite electrode connection cannot be forcibly pulled to prevent the line connector from breaking.
3. After turning on the power switch, switch to the PH measurement file.
4. Measure the temperature of the PH6.86 standard solution with a thermometer, and then adjust the temperature compensation knob of the PH meter to the measured temperature value.
5. Rinse the composite electrode with deionized water and dry it with filter paper.
6. Pour 2-5ml of the PH6.86 standard solution into a plastic beaker that has been washed and dried with water. After washing the beaker and the composite electrode, pour it out, then add 20ml of the pH6.86 standard solution into the plastic beaker, and insert the composite electrode into the plastic beaker. In the solution, use the instrument positioning knob to adjust to a reading of 6.86 until it stabilizes. The following two points should be noted:
(1) The bit must be adjusted with the PH6.86 standard.
(2) After the adjustment, the positioning knob must not be moved again.
7. Wash the composite electrode with deionized water, dry it with filter paper, measure the temperature of the PH4.00 solution with a thermometer, and adjust the temperature compensation knob of the instrument to the measured temperature value.
8. Pour 2-5ml of the PH4.00 standard solution into another plastic beaker, wash the beaker and the composite electrode, and pour it out, then add 20ml of the pH4.00 standard solution, insert the composite electrode into the solution, and after the reading is stable, use the slope knob to Adjust to pH 4.00. It should be noted that after the slope knob is adjusted, it must not be moved again.
9. Measure the temperature of the liquid to be tested with a thermometer, and adjust the temperature compensation of the instrument to the measured temperature.
10. Insert the composite electrode into the solution to be tested, and read the pH value, which is the pH value of the solution to be tested. The following two points should be noted:
(1) The temperature should not be too high during the measurement. If the measurement result is inaccurate over 40°C, take it out with a beaker and cool it slightly.
(2) Avoid contacting the composite electrode with organic matter, and clean it with anhydrous ethanol once contacted or contaminated.
11. Precautions: The instrument must be calibrated before use, that is, the above 4 to 8 operations. If the instrument is not turned off, it can measure continuously, and it needs to be calibrated once it is turned off. However, it must be calibrated once every 12 hours even if the machine is not turned off.
