One-point calibration and operating procedures of pH meter
Any pH meter must be calibrated with a pH standard solution before measuring the pH value of the sample. For samples with measurement accuracy below 0.1 pH, the instrument can be adjusted using a point of extreme accuracy method, generally using pH 6.86 or pH 7.00 standard buffer solution. Some instruments have an accuracy of only 0.2pH or 0.1pH, so the instrument only has one "positioning" adjustment knob. The specific operation steps are as follows:
(1) Measure the temperature of the standard buffer solution, check the table to determine the pHs value at that temperature, and adjust the temperature compensation knob to that temperature.
(2) Rinse the electrode with pure water and shake dry.
(3) Immerse the electrode in the buffer solution and shake it before standing still. After the reading is stable, adjust the positioning knob to make the instrument display the pH value of the standard solution.
(4) Remove the electrode, rinse and shake dry.
(5) Measure the temperature of the sample and adjust the pH meter temperature compensation knob to that temperature value
1. Does the online pH meter transmitter screen display "E.rr"?
Answer: PH exceeds the range. Possible: Indicates that the electrode wiring is disconnected.
2. Does the number of the online pH meter transmitter jump randomly and not match the water quality?
Answer: It may indicate a leakage at the reference connection point. Try wiping the connection terminal with anhydrous alcohol and keeping the humidity at the connection point to meet technical requirements.
3. Is there no control signal output from the online pH transmitter?
Answer: Check if the screen is in normal mode.
4. Do you feel that the measurement value of the online transmitter is inaccurate?
Answer: Remove the electrodes of the online pH meter and clean and calibrate them according to the instructions. If calibration is not possible during the pH meter calibration process, please try replacing the electrodes.
5. Is the electrode reaction slow?
Answer: When the temperature is low, the internal resistance of the electrode increases and the reaction will be slower. When the bubble is covered with dirt and the liquid interface is blocked by dirt, the reaction will slow down. Please try cleaning the electrode.
6. Does the pH of the electrode remain unchanged when placed in any solution?
Answer: The electrode bulb has ruptured and the electrode needs to be replaced. The electrode and instrument wiring have come loose, please check. The electrode cable is internally broken, please replace or send it back for repair.
