The pH controller is an digital intelligent pH meter for water/food pH value or ORP value testing and monitoring.

Application:
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.

Function:

• 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.

Specification:

The pH meter and pH/ORP electrode selection:

Wiring diagram:

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

Communication:
RS485 communication data and register address as follows:

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.