Tenber PHS-3301

PHS-3301 pH/ORP Controller with RS485 Modbus

144 mm industrial pH/ORP controller with dual isolated 4–20mA outputs, RS485 Modbus RTU, three relay functions and 500,000-record data logging.

Tenber PHS-3301 pH ORP Controller
ENGINEER-READY WATER QUALITY INSTRUMENT

Built for continuous process monitoring

144 mm industrial pH/ORP controller with dual isolated 4–20mA outputs, RS485 Modbus RTU, three relay functions and 500,000-record data logging.

Key specifications

Measurement Range -2.00 to 16.00 pH / -2000 to 2000 mV
Temperature Range -10.0 to +150.0°C
Output 4-20mA and RS485 Modbus RTU
APPLICATION-BASED QUOTATION

Need help confirming the right controller and sensor?

Not sure which controller and sensor fit your process? Send us the liquid, measuring range, temperature, installation method, required output and quantity. We will review the configuration before quotation.

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    Technical author: Tenber Technical Team Technical reviewer: Tenber Technical Team Last updated: August 21, 2026 Documentation source: current model manual / technical guide and quality documents. Confirm scope for the supplied model.

    Product Overview

    144 MM PH / ORP CONTROL

    How to Select the Right Configuration

    Choose PHS-3301 when the project needs a 144 mm controller, two isolated 4–20mA outputs, RS485 Modbus RTU, two measurement relays, a multifunction relay or documented data logging. If the panel only needs one analogue output and two relays, compare the compact PH-302. If the requirement is limited to two isolated analogue outputs without verified RS485 or relay functions, compare PH-303.

    Key Functions and Benefits

    Key Functions

    pH, ORP and temperature

    Measure pH or ORP with temperature display and compensation. The documented ranges are −2.00 to +16.00 pH, −2000 to +2000 mV and −10.0 to +150.0°C for temperature measurement and compensation.

    Two isolated current outputs

    Current output A can be assigned to pH, ORP or temperature, and current output B provides the second configured measurement channel. Each output is isolated, supports a maximum 500Ω load and can be scaled between 4.00 and 20.00mA.

    Control, cleaning and alarms

    Relay A and Relay B provide configurable action and release points. Relay C is a multifunction relay for automatic cleaning, cycle alarm or error alarm, with a documented 0–120 second delay setting.

    Verified Technical Specifications

    Verified Technical Specifications

    Measured variablespH / ORP / temperature
    pH range−2.00 to +16.00 pH
    ORP range−2000 to +2000 mV
    Resolution0.01 pH / 1 mV / 0.1°C
    Accuracy±0.01 pH / ±1 mV / ±0.2°C
    Temperature compensationPt1000 or NTC10K; manual compensation is also documented
    Temperature range−10.0 to +150.0°C measurement and compensation
    Analogue outputsTwo isolated 4–20mA outputs; maximum load 500Ω; output accuracy ±0.05mA
    CommunicationRS485 Modbus RTU; address 1–255; 9600 / 19200 / 38400 baud
    Relay functionsTwo measurement relays plus one multifunction relay; 5A/250VAC or 5A/30VDC
    Data loggingUp to 500,000 records; optional USB for download and software update
    Cleaning functionON 1–1000 seconds; OFF 0.1–1000.0 hours
    Protection and powerIP65; 90–260VAC; power consumption below 5W
    InstallationPanel, wall or pipe mounting; 141 × 141mm panel opening; approximately 0.85kg

    Sensor, Range and Compatibility

    Dual analogue outputs and Modbus integration for continuous process measurement

    Tenber PHS-3301 is a 144 mm industrial pH/ORP controller for continuous pH, oxidation-reduction potential and temperature measurement. The documented controller provides two isolated 4–20mA outputs, RS485 Modbus RTU communication, two measurement relays and a multifunction relay for cleaning, cycle or error alarm functions.

    It is intended for projects such as wastewater treatment, environmental monitoring, fermentation, food production and compatible dosing-control arrangements. The final controller, electrode, temperature probe, installation and control logic should be selected from the actual liquid and operating conditions.

    −2–16 pHpH measuring range
    ±2000 mVORP measuring range
    2 × 4–20mAIsolated outputs
    500,000Documented records

    Sensor and Temperature-Probe Selection

    PHS-3301 should be specified with the electrode and temperature arrangement as one measuring loop. The controller can be used with a pH or ORP electrode, but the correct sensor depends on the liquid composition, expected range, temperature, pressure, installation position, fouling and cleaning method.

    TB84H0

    Consider for standard industrial pH measurement after confirming the liquid, temperature, pressure, thread and cable requirements.

    TB84H7W

    Consider for selected fluoride-containing media. HF resistance does not establish universal chemical compatibility; provide the complete chemistry for review.

    TB84R1

    Use for suitable oxidation-reduction measurements after confirming the expected ORP, chemicals, temperature, pressure and installation.

    For automatic temperature compensation, match the connected probe to the selected Pt1000 or NTC10K setting. Manual temperature compensation is available when the process arrangement calls for a fixed temperature input. Confirm the electrode connector, temperature probe, cable and controller terminal assignment before wiring.

    Outputs, Modbus and Relay Configuration

    Scale each 4–20mA output to the measurement value required by the receiving PLC, recorder or DCS. The manual documents separate pH/ORP and temperature output settings, reversible 4.00mA and 20.00mA endpoints, output offset and a 0–120 second software filter time. Verify the mapping, isolation, load and signal direction with the receiving system before commissioning.

    RS485 Modbus RTU settings include a device address from 1 to 255 and selectable 9600, 19200 or 38400 baud. Confirm the register map and communication parameters for the supplied configuration. Relay action and release points should be set from the process logic, and inductive or capacitive loads should use appropriate contact protection.

    Typical Applications

    Typical Applications

    Wastewater Neutralization

    Monitor pH or ORP during acid and alkali dosing, treatment and discharge processes after the electrode and sample point are matched to the wastewater.

    Environmental and Process Water

    Transmit pH, ORP and temperature values to compatible automation or recording equipment through isolated analogue outputs or Modbus RTU.

    Fermentation and Food Production

    Use continuous pH or temperature observation where the liquid, cleaning method, sensor materials and installation conditions have been reviewed.

    Installation, Commissioning and Maintenance

    Installation, Commissioning and Calibration

    1. Confirm the PHS-3301, electrode, temperature probe, cable, mounting arrangement and power supply before installation.
    2. For panel mounting, prepare the documented 141 × 141mm opening. Wall and pipe mounting use the supplied 144-series mounting arrangement.
    3. Connect the pH or ORP electrode and temperature probe exactly as shown in the current manual. Remove the conductive rubber layer from the pH electrode cable where the manual requires it.
    4. Choose pH or ORP mode, select automatic or manual temperature compensation and set the display and filter values.
    5. Complete the first pH calibration point, then add a second or third point when the process range requires it. ORP uses manual calibration with a suitable reference solution.
    6. Check the displayed value against an accepted reference procedure before enabling automatic dosing or alarms.
    7. Test both current outputs and all relay functions. Set Relay C to cleaning, cycle alarm or error alarm only after the control-system behavior is understood.
    8. Record cleaning, calibration and electrode-efficiency observations. The manual identifies efficiency below 80% as an indication that the electrode may be ageing.

    Frequently Asked Questions

    Frequently Asked Questions

    How many 4–20mA outputs does PHS-3301 provide?

    The manual documents two isolated 4–20mA outputs with a maximum 500Ω load. Confirm the pH/ORP and temperature mapping for the supplied configuration.

    Does PHS-3301 support RS485 Modbus RTU?

    Yes. The documented communication interface is RS485 Modbus RTU with selectable 9600, 19200 or 38400 baud rates and an address range of 1–255.

    What does the third relay do?

    The third multifunction relay can be configured for cleaning, cycle alarm or error alarm. Relay delay and complete control logic must be checked before connection to a field device.

    How many records can the controller store?

    The manual documents storage of up to 500,000 records. An optional USB interface can be used for record download and software update, subject to the documented USB capacity limit.

    Which electrode should I choose?

    Send the liquid composition, pH or ORP range, temperature, pressure, mounting, cable and cleaning conditions. The controller, electrode and temperature probe should be reviewed together.

    Compare the industrial pH and ORP controller range, review the sensor and electrode options, or read the wastewater pH monitoring guide.

    PROJECT SELECTION SUPPORT

    Manuals, Related Products and Request for Quotation

    Confirm the PHS-3301 measuring configuration

    Send the liquid, pH or ORP range, temperature, pressure, mounting, output, Modbus, relay and data-logging requirements. Tenber will review the controller and sensor combination before quotation.

    Request a Quote

    Selection flow for PHS-3301

    Start with pH or ORP measurement, then check the complete measuring loop before quotation.

    1. Define the application and liquid composition.
    2. Record the normal and maximum value, temperature, pressure and flow conditions.
    3. Choose the sensor or electrode, installation method, cable and maintenance access together with the controller.
    4. Confirm the receiving system, including 4–20mA, RS485 Modbus RTU, relay, recorder, PLC or DCS requirements.
    5. Send the quantity, destination country and current documentation requirement for model review.

    Application boundaries

    Confirm the required channels, RS485 Modbus RTU functions, relay logic, records, electrode and panel installation against the current model documentation.

    Inquiry checklist

    Include the liquid, parameter and range, temperature, pressure, installation, sensor or electrode, cable length, output or communication interface, control requirement, quantity and destination country.

    Typical Applications

    This model is intended for continuous industrial water-quality monitoring. Typical project uses include:

    Key Selection Points

    Confirm the measuring range, sensor material, installation method and signal requirements before ordering. The correct electrode or sensor should be selected according to the liquid, temperature, pressure and chemical conditions.

    Information Required for Model Selection

    Frequently Asked Questions

    How do I confirm whether this model suits my process?

    Send Tenber your process conditions and required signals. We will check the controller and sensor configuration before quotation.

    Can the sensor be selected separately?

    Yes. Sensor selection depends on the medium, range, temperature, pressure and installation method. Please provide these details with your inquiry.

    What support is available after purchase?

    Tenber provides model-selection guidance, installation documentation and technical assistance for supplied products.