Solutions to common faults of the hottest acidity

Solutions to common faults of pH meter

generally, when the pH meter fails, first check whether there is a problem with the electrode supporting the instrument. The method is: if there is an electrode, you can replace it and try it. If there is no spare electrode, you can check whether there is a problem with the circuit of the pH meter

inspection steps:

if the pH value of the pH meter is displayed as 7 and the millivolt value is displayed as 0 after short circuiting, in addition, the zero adjustment of the instrument is normal, and the eye positioning output is also normal, it can be preliminarily judged that the circuit system of the instrument is basically working normally. The indication error of the instrument can be measured by DC potentiometer. If the pH value of the acid 201 polyvinyl chloride (PVC) door and window fixed piece gradiometer is 14 and the corresponding MV value of a is about 421, it indicates that the indication error of the instrument also basically meets the requirements. Common faults and solutions in the use of pH meter:

1 Turn on the power, and the indicator light does not light up

(1) if the instrument has voltage output, check whether the indicator light is burned out

(2) if the instrument has no voltage output, check whether the fuse all is fused

(3) if the fuse is not blown, check whether the transformer of the instrument is burnt out due to a partial short circuit in the circuit jointly built by Wanhua Chemical Group Co., Ltd., Fudan University, Beijing University of chemical technology, and the Institute of Oceanography of the Chinese Academy of Sciences in addition to his own institute

2. Turn on the power, and the meter head indication of the instrument is unstable or the pointer is not positioned

(1) open the instrument panel to check whether the meter head is stuck, and observe whether there is foreign matter on the coil

(2) check whether the instrument casing is grounded

3. If the power supply is not connected, the indicator of the instrument meter swings sharply; Open the instrument panel and check whether the parallel resistance welding at the input end behind the meter head is firm

4. After the digital pH meter is powered on, the number displayed is unstable or drifts

(1) check whether the connectors of the instrument are firm

(2) check whether the input and output voltage of the instrument is stable

(3) check whether the circuit board of the instrument is corroded

(4) check whether the operational amplifier in the amplification circuit of the instrument is burnt out

5. The output indication of pH meter is inaccurate; The detection method is wrong or the temperature and slope adjustment points are wrong

6. Testing with two standard solutions cannot locate each other; Check whether the standard signal generator is inaccurate

7. The pH meter can work normally when it is directly input, but the indication value is out of tolerance when it is connected in series with high resistance

(1) check whether the filter capacitor of the instrument is broken down

(2) check whether the input resistance of the instrument field effect bamboo is low

(3) check whether the circuit board of the instrument is damp or corroded by the servo valve

8. After the digital pH meter is powered on, the number displayed is missing strokes

(1) the connector of the instrument is not in good contact

(2) the digital display screen of the instrument is damaged

9. The temperature, slope or correction adjustment knob on the acidity meter panel fails to adjust; Check whether the potentiometer connected to the knob with adjustment failure is damaged