(1) The instrument should be stored in a cool and dry place. If not in use for a long time, regular power on inspection and maintenance should be carried out, especially during the rainy season, and regular inspections should be carried out. When using, do not spill the solution onto the instrument.
(2) The working power supply of the instrument should meet the requirements and should not be connected incorrectly. AC powered instruments have a slightly longer preheating time before measurement and are generally allowed to operate continuously with power on. When the measurement interval is not long, there is no need to underclose the power supply. This is beneficial for the stable operation of the instrument. Dry battery powered instruments have a shorter preheating time, and intermittent star measurement can be used as needed, saving electricity. Regularly check the battery voltage. When used for a long time, the battery should be removed to prevent leakage of electrolyte through the battery casing and corrosion of the instrument.
(3) The power supply wiring of the acidity meter powered by AC adopts a single-phase three wire connection element, connected to a good "ground" wire to ensure safety and prevent electromagnetic field interference. Instruments powered by direct current. When electromagnetic field interference affects the normal operation of the instrument, the "ground" line can be connected to eliminate the interference.
(4) The installation and operation of instruments should comply with the requirements specified in the mixing book. The working position of the instrument should meet the requirements and avoid vibration. The electrode bracket clamp should be securely fastened to prevent damage to the electrode.
(5) The temperature compensator of the acidity meter should be adjusted according to the actual temperature of the measured solution. The fastening screw of the button should not be loose, otherwise it should be rechecked according to the prescribed method.
(6) Before measuring the test solution, the "positioning" of the standard buffer concentration calibration instrument that is close to the pH value of the test solution should be selected. After calibration, the adjustment knob should not be turned, otherwise it should be recalibrated. After the measurement of a batch of test solution is completed or there is doubt about the measurement results, the "positioning" of the instrument should be checked. If there is any change, it should be recalibrated before measuring the pH value of the test solution. Generally, each test solution should be measured at least once.
(7) After each use, maintenance and upkeep of the instrument should be carried out: turn off the power, clean the instrument, cover the instrument cover or place it in the instrument box.
(8) Normally used instruments should be checked for accuracy and reproducibility of readings using several standard buffer solutions every few days. When high measurement accuracy is required, it should be checked before each measurement. Generally, a mixed phosphate standard buffer solution can be used to calibrate the "positioning", and then potassium hydrogen phthalate and borax standard buffer solutions can be measured separately, repeating three to five times. The indication error and reproducibility should comply with the technical specifications specified by the instrument. If there are any problems, the cause should be identified.
(9) Normally used instruments should be calibrated regularly once a year according to the calibration regulations. If you have doubts about the accuracy and performance of the instrument, you can always use several standard buffer solutions for calibration according to conventional methods. When necessary, comprehensive calibration of the main technical performance indicators of the instrument should be carried out.
(10) In addition to paying attention to the above points when using an acidity meter, maintenance work should also be done according to the different characteristics and requirements of various types of instruments.