Digital pH meter is an intelligent industrial online pH controller for water/food pH value or ORP value testing and monitoring.
Digital pH/ORP meter 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: Buzzer, LCD backlight, password, pH/ORP electrode, manual/automatic temperature compensation, pH/ORP calibration, pH/ORP modification, pH/ORP high/low alarm, output signal 4-20mA and RS485, etc.
- Internal industrial watchdog insures pH meter don't crash.
||96*96*112mm (H*W*D) with hole size 93*93mm
||pH: 0~14pH, ORP: -1000~1000mV (-2000~2000mV need customization)
||0~100℃ (NTC 10K, 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.)
|Power supply *
||AC 220V±10%, 50Hz/60Hz
AC 110V±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
- TEMP2: Temperature compensation terminal 2
- TEMP1: Temperature compensation terminal 1
- 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 (+)
- LO (AL): Low alarm
- HI (AH): High alarm
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: How to control the pH value to be 6-9 with a pH meter?
The pH electrode with submersible installation is submerged in the alkali pool to test the pH value. The lower limit alarm relay of the pH meter is connected to a solenoid valve (normally closed solenoid valve).
First, set the lower alarm value to be 6 for closed and 7 for open, when the pH value is below 6, the alarm relay is closed and the dosing pump works to add lye to the pool. When pH value in the pool reaches 7, the alarm relay is closed, and the dosing pump stops to add lye.
Second, set the upper alarm value to be 9 for closed and 8 for open, when the pH value is above 9, the alarm relay is closed and the dosing pump works to add acid liquor to the pool. When pH value in the pool reaches 8, the alarm relay is close and the dosing pump stops to add acid liquor.
Through the alarm return difference, pH value will be controlled between 6 and 9.