The pH controller is an digital intelligent pH meter for water/food pH value or ORP value testing and monitoring.
The pH/ORP controller is widely used in the continuous testing and monitoring of pH, ORP and temperature in thermal power, chemical fertilizer, metallurgy, environmental protection, pharmaceutical, biochemical, food, drinking water, etc.
- 2.4 inch LCD display
- Good anti-interference performance
- Manual/automatic temperature compensation
- User settings: Language, buzzer, LCD backlight, password, pH/ORP electrode, manual/automatic temperature compensation, pH/ORP calibration, pH/ORP/temperature modification, pH/ORP high/low alarm, output signal 4-20mA and RS485, etc.
- Internal industrial watchdog insures pH meter don't crash.
||100*100*150mm (H*W*D) with hole size 93*93mm
||pH: 0~14pH, ORP: -1000~1000mV (-2000~2000mV need customization)
||-10~+130℃ (NTC 10K or PT1000, accuracy: ±0.5℃)
|Output signal *
||Isolated 4-20mA signal (error: ±0.1%, under maximum loop resistance 750Ω)
|Communication function *
||RS485 with standard MODBUS-RTU (Now RS485 software is free.)
||AC 220V±10%, 50Hz/60Hz
||2 alarm relays: AC 250V/3A
Function: high alarm, low alarm
The pH meter and pH/ORP electrode selection:
||Combination pH electrode
||Combination electrode has automatic temperature compensation function, suitable for occasions with large temperature fluctuations.
|Pure water pH electrode
||The pH calomel electrode can be used in strong acid or alkali.
|PTFE pH electrode
||The electrode shell is made of PTFE, suitable for corrosive solution (strong acid or alkali), has longer life in harsh environments.
|pH glass electrode
||Sewage disposal / food
||Direct lead, double-layer glasses.
|Desulfurization pH electrode
||Flat electrode, strong anti-pollution ability and longer life
|High temperature/sterilization pH electrode
||The electrode can withstand high temperature of 0-130℃, suitable for occasions of high temperature sterilization in pharmaceutical factories, breweries, etc.
|High pressure/accuracy pH electrode
||Its linearity and accuracy are higher than all above electrodes.
Definition of the ports:
- INPUT: Measuring terminal of the electrode
- REF: Reference terminal of the electrode
- NC: Undefined
- A: Temperature compensation terminal A, connect to NTC 10K or PT1000
- B: Temperature compensation terminal B, connect to NTC 10K or PT1000
- C: Temperature compensation terminal C, connect to 3-wire PT1000 GND (3-wire PT1000), or connect to B (2-wire PT1000), or NC (NTC 10K)
- RS485 (A+): RS485 communication interface A+
- RS485 (B-): RS485 communication interface B-
- 4-20mA (+): 4-20mA output terminal +
- 4-20mA (-): 4-20mA output terminal -
- AC 220V/110V (L) or DC 24V (-): AC 220V/110V live wire or DC 24V (-)
- AC 220V/110V (N) or DC 24V (+): AC 220V/110V neutral wire or DC 24V (+)
- HO: Normally-open relay for high alarm
- HC: Normally-closed relay for high alarm
- LO: Normally-open relay for low alarm
- LC: Normally-closed relay for low alarm
- COM: Common terminal
RS485 communication data and register address as follows:
||PH value (default in two decimals)
||Temperature value (default in one decimals)
||ORP value (signed integer)
Tips: Different types of pH meters
Pen type (mini) pH meter and portable pH meter are generally used by testing personnel on site. Portable pH meter and benchtop pH meter are common instruments with wide measuring range, the difference is that portable pH meter uses the DC power supply, so it can be taken to work field. Laboratory pH meter has wide measuring range, various functions and high measurement accuracy.
Industrial online pH meter is more stable and reliable and have a certain measurement accuracy, strong environmental adaptability and strong anti-interference ability, as well as functions of analog output, digital communication, upper and lower limit alarm, control function, etc. For a measurement at 20～30℃ and pH value 7, there is no need temperature compensation. For a measurement at a temperature above 30℃ or below 20℃ while the pH value is higher than 8 or lower than 6, temperature variation must be compensated.