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    Digital pH/ORP Meter for Water Testing

    The digital pH/ORP meter is a pH/ORP controller for testing water quality, which can transmit the standard output signal 4-20mA to the digital panel meter/VFD/PLC/logger, or transmit the RS485 signal to the computer for remote monitoring and recording. The pH meter works for testing and monitoring the pH of sewage, corrosive solutions, liquid pharmaceuticals, beer, drinking water, food, etc.
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    🔙 30-day returns
    📅 Delivery: 7-12 days

    The digital pH meter is output to the monitoring room for record preservation through RS485 or current transmission, and historical data can be viewed through the record option. The sisco meter is widely used in thermal power, chemical fertilizer, metallurgy, environmental protection, pharmaceutical, biochemical, food, and water industries.

    pH meter watchdog protection system design

    Watchdog protection system, strong anti-interference ability

    • 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 doesn't crash.



    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.

    pH meter applications

    Model SISCO-PHCR-PH160
    Weight 1kg
    Dimension 96*96*100mm (H*W*D) with hole size 92*92mm
    Measuring range pH: 0~14pH, ORP: -1000~1000mV (-2000~2000mV can be customizable)
    Accuracy ±0.02pH, ±1mV
    Resolution ±0.01pH, ±1mV
    Stability ≤0.02pH/24h, ≤3mV/24h
    Input impedance ≥10^12Ω
    Temperature range 0~100℃ (NTC 10K, accuracy: ±0.5℃)
    Temperature compensation 0~100℃ manual/automatic
    Output signal Isolated 4-20mA signal (error: ±0.2%, under maximum loop resistance 750Ω)
    Communication function RS485 with standard MODBUS-RTU (Now RS485 software is free.)
    Power supply AC 220V±10%, 50Hz/60Hz
    DC 24V
    Alarm relay 2 alarm relays: AC 250V/3A
    Function: high alarm, low alarm

    The pH meter and pH/ORP electrode selection

    pH meter pH/ORP electrode Industry Temperature range Advantage
    SISCO-PHCR-PH160 Combination pH electrode Sewage disposal 0-60℃ (32-140℉) Combination electrode has automatic temperature compensation function, suitable for occasions with large temperature fluctuations.
    Pure water pH electrode Drinking water 0-60℃ (32-140℉) The pH calomel electrode can be used in strong acid or alkali.
    PTFE pH electrode Chemical 0-60℃ (32-140℉) 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 0-95℃ (32-203℉) Direct lead, double-layer glasses.
    Desulfurization pH electrode Desulfurization 0-60℃ (32-140℉) Flat electrode, strong anti-pollution ability and longer life
    High temperature/sterilization pH electrode Food 0-130℃ (32-266℉) 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 Laboratory 0-80℃ (32-176℉) Its linearity and accuracy are higher than all above electrodes.

    The pH/ORP meter diagram of ports definition

    pH ORP meter wiring diagram


    RS485 communication data and register address as follows:

    Address Data type Function code Explanation Access right
    0x0000 unsigned short 0x03 pH value (default in two decimals) Read only
    0x0001 unsigned short 0x03 Temperature value (default in one decimals) Read only
    0x0002 short 0x03 ORP value (signed integer) Read only

    Q1: What is the working principle of a pH meter?
    A1: The pH meter works on the principle of a galvanic battery. The electromotive force between the two electrodes of the galvanic battery is based on Nernst's law, which is not only related to the properties of the electrodes, but also to the concentration of hydrogen ions in the solution. There is a the corresponding relationship between the electromotive force of the primary cell and the hydrogen ion concentration, and the negative logarithm of the hydrogen ion concentration is the pH value.

    Q2: The same sample is measured on two pH meters at the same time, why are the readings inconsistent?
    A2: Because the calibration conditions of the two pH meters are different (such as calibration done at different times), the measured values are different. Therefore, the pH meter should be calibrated at the same time with the same buffer, and then measured at the same time.

    Q3: How do I know if the pH meter is accurate?
    A3: Take three standard buffer solutions: pH 6.86, pH 4.00, pH 9.18 (preferably freshly prepared and at the same temperature), position calibration at pH 6.86, slope calibration at pH 4.00, and then test pH 9.18 to know the pH meter Is it accurate.

    Tips: What is 1 point calibration of the pH meter?

    Any kind of pH meter must be calibrated by pH standard solution before measuring the pH value of samples. For samples with measurement accuracy below  0.1pH, one point calibration method can be used to adjust the instrument, usually pH 6.86 or pH 7.00 standard buffer solution is used. Some instruments only have 0.2pH or 0.1pH, so the instrument only has a positioning adjustment twist, the specific operation steps are as follows.

    • Measure the temperature of the standard buffer solution, check the table to determine the pH value at that temperature, and adjust the temperature-tasting knob to that temperature.
    • Rinse the electrode with pure water and shake it dry.
    • Immerse the electrode in the buffer solution and shake it to rest. After the reading is stable, adjust the positioning knob to make the instrument display the pH value of the standard solution.
    • Remove the electrode, rinse and shake dry.
    • Measure the temperature of the sample and adjust the temperature compensation knob of the pH meter to that temperature value.
    • Immerse the electrode into the sample solution, shake it and leave it at rest, then read the value when the display is stable

    Thank you for buying industrial test and measurement equipment on, all products sold by SISCO and the partner cover a 12 months warranty, effective from the date of receiving the products.

    What is covered?

    SISCO is responsible for providing free spare parts, and free technical support to assist the customer to repair the defective products until the problem is solved.

    What is not covered?

    • Product purchased from anyone other than a SISCO store or a SISCO authorized reseller.
    • Expendable parts.
    • Routine cleaning or normal cosmetic and mechanical wear.
    • Damage from misuse, abuse or neglect.
    • Damage from use of parts other than SISCO approved.
    • Damage from use outside the product’s usage or storage parameters.
    • Damage from use of parts not sold by SISCO.
    • Damage from modification or incorporation into other products.
    • Damage from repair or replacement of warranted parts by a service provider other than a SISCO authorized service provider.
    • Damage caused by the application environment not meeting the product usage requirements and the failure to perform preventive maintenance.
    5.0 1
    Write your own review Close
    patryk | 3/7/2023 5:57 PM
    Accurate pH/ORP meter
    I received this digital pH/ORP meter earlier than I expected, I use it as soon as I  received it. I have used it in water quality tests in different places, it is accurate. The screen of this pH meter is very large, and I can see it clearly.