Common Malfunctions of PH Meter
1,No response when switching on
Fault causes: 1) the circuit is not connected; 2) external voltage instability; 3) instrument damage.
Troubleshooting methods: 1) check whether the power supply voltage output; 2) external voltage regulator power supply instruments, if the boot does not respond, check the output of the regulator power supply, there should be 9V DC voltage; 3) according to the provisions of the replacement or repair.
2, no display on the boot
Failure causes: 1) LCD screen and the motherboard wiring potential mismatch; 2) the motherboard connected to the LCD screen connecting line poor contact or instrument damage.
Troubleshooting: 1) if the power on the backlight is bright, but no display of digital, adjust the potentiometer on the motherboard; 2) according to the regulations of the replacement or repair.
3, the boot display error, Err words appear
Failure causes: desktop or portable pH meter generally have a self-test function, when the instrument detects problems with the storage chip, will display this information.
Troubleshooting: switch off, wait a moment, restart the pH meter several times, if the problem still exists, the chip can not be recovered, please contact a professional engineer for maintenance.
4,Instrument mV area error or incorrect measurement
Failure causes: 1) when the input potential exceeds the measurement range, the instrument will display the mV area "Err"; 2) electrode performance is not good; 3) the measurement channel is set incorrectly; 4) electrode plug contact is poor.
Remedy: 1) reduce the input value; 2) replace the electrode with a good one; 3) reset the measurement channel; 4) connect the short-circuit plug, the instrument should display 0.0mV or so, otherwise there is a problem with the pH measurement unit.
5,pH measurement is not correct
Failure causes: 1) electrode performance is not good; 2) the measurement channel is set incorrectly; 3) the electrode is not calibrated or calibrated incorrectly.
Remedy: 1) replace the electrode with good performance; 2) reset the measurement channel; 3) recalibrate the electrode or replace the standard liquid.
6, pH meter in the measurement of instability
Failure causes: 1) whether the electrode interface is loose; 2) in the determination of pure water or demineralised water is unstable due to water impurities, poor conductivity.
Remedy: 1) available short-circuit plug into the instrument, such as the display is stable, you can consider switching electrodes;
(2) with a standard buffer for correction.
7, for portable touch screen pH meter, touch screen positioning is not allowed.
Failure causes: drift phenomenon for a long time.
Remedy: Recalibrate the touch screen in the instrument settings.
