Digital pH/ORP meter is an industrial pH/ORP meter 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.
- 2.8 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.
||pH: 0~14pH, ORP: -1000~1000mV (-2000~2000mV need customization)
||-10~+130℃ (NTC 10K, accuracy: ±0.5℃)
||Isolated 4-20mA signal (error: ±0.1%, under maximum loop resistance 750Ω)
||RS485 with standard MODBUS-RTU (Now RS485 software is free.)
||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.
The pH/ORP meter diagram of ports definition:
- INPUT: Measuring terminal of the electrode
- REF: Reference terminal of the electrode
- 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 (I+): 4-20mA output terminal +
- 4-20mA (I-): 4-20mA output terminal -
- 12V (+): 12V output terminal + (this model is not available)
- 12V (-): 12V output terminal - (this model is not available)
- COM: Common terminal
- LC: Normally-closed relay for low alarm
- LO: Normally-open relay for low alarm
- HC: Normally-closed relay for high alarm
- HO: Normally-open relay for high alarm
- AC 220V/110V (L) or DC 24V (-): AC 220V/110V live wire or DC 24V (-)
- NC: Undefined
- AC 220V/110V (N) or DC 24V (+): AC 220V/110V neutral wire or DC 24V (+)
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: Why should the pH meter be recalibrated?
After the calibration is completed, the frequently used pH meter does not need to be calibrated again within 48 hours. In case of any of the following situations, the meter needs to be recalibrated:
- There's a huge difference between solution temperature and calibration temperature.
- The electrode has been exposed in the air for too long, such as more than half an hour.
- Position or slope adjuster is moved by mistake.
- Peracid solution (pH＜2) or overbasic solution (pH＞12) is measured.
- The electrode is replaced.
- pH value of the measured solution is not in the middle of the calibrated value for two points while it's far from 7pH.