Built for continuous process monitoring
PH-302 industrial pH/ORP controller for wastewater and process monitoring with isolated 4–20mA, RS485 Modbus RTU and two relay controls.
Key specifications
| Measurement Range | -2.00 to 16.00 pH / -2000 to 2000 mV |
| Communication | RS485 Modbus RTU |
| Relay | 5A/250VAC, 5A/30VDC on selected model |
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.
Product Overview
PH-302 Industrial pH/ORP Controller for Online Monitoring
The Tenber PH-302 is an industrial pH/ORP controller for continuous monitoring in wastewater treatment, chemical dosing and process-liquid applications. It supports an isolated 4–20 mA output, RS485 Modbus RTU communication and two relay control points. Panel, wall and pipe mounting options help integrators and plant engineers match the controller to the installation.
Send your liquid conditions, measurement range and control requirements to confirm the suitable PH-302 controller and electrode configuration.
How to Select the Right Configuration
Use PH-302 when the documented −2 to +16 pH or ±2000mV ORP range, one isolated 4–20mA output, RS485 Modbus RTU and two relay controls match the project. Send the liquid composition, expected range, temperature, pressure, mounting method, cable length, control logic and quantity so Tenber can confirm the controller and sensor combination before quotation.
Key Functions and Benefits
Key Functions
pH or ORP measurement
Select the pH or ORP measurement mode from the controller settings. The documented resolution is 0.01 pH or 1 mV, with a large backlit colour LCD for process readings.
Analogue and digital signals
The documented isolated 4–20mA output can be scaled to the selected pH or ORP range. RS485 Modbus RTU communication is available on PH-302 with selectable 9600, 19200 or 38400 baud rates.
Two relay control points
Relay 1 and Relay 2 can be configured with separate action and release points. Confirm the required control logic and use suitable external protection for inductive or capacitive loads.
Verified Technical Specifications
Verified Technical Specifications
Sensor, Range and Compatibility
Sensor, Temperature and Signal Selection
PH-302 can be used with a pH or ORP electrode, but the final sensor depends on the liquid, expected range, temperature, pressure, installation method and maintenance conditions. Tenber’s compatible options include TB84H0 for standard industrial pH measurement, TB84H7W for HF-resistant pH applications and TB84R1 for industrial ORP measurement. Confirm the electrode, connector and cable before ordering.
Choose Pt1000 or NTC10K when automatic temperature compensation is required, or use the documented manual mode when the process arrangement calls for a fixed temperature input. The controller also provides a pH/ORP offset setting; use it only after the displayed value has been checked against an accepted reference.
Typical Applications
Typical Applications
Wastewater Monitoring
Monitor pH or ORP during neutralization, treatment and discharge processes after the electrode and sample point are matched to the liquid.
Process and Environmental Water
Transmit the measurement to compatible PLC, DCS or recording equipment through isolated 4–20mA or RS485 Modbus RTU.
Fermentation and Food Production
Use continuous pH or temperature observation where the materials, cleaning conditions and electrode arrangement have been reviewed.
Installation, Commissioning and Maintenance
Installation and Wiring Considerations
The 96-series body supports panel, wall and pipe installation. For panel mounting, prepare a 92.5 × 92.5mm square opening and secure the instrument with the supplied mounting hardware. Install the controller away from high heat, high humidity, corrosive gases, direct sunlight and sources of electrical interference.
Complete the electrode, temperature, 4–20mA, RS485, relay and power wiring before applying power. The manual identifies the PH/ORP, reference, auxiliary, shield, temperature, current-output and RS485 terminals. Check polarity, signal mapping and the receiving device before connecting the controller to a PLC, DCS, recorder or dosing system.
Relay contacts can be affected by electrical sparks, especially with inductive or capacitive loads. Follow the manual’s protection guidance and use an appropriately rated external protection circuit where the connected load requires it.
Commissioning, Calibration and Maintenance
- Confirm the controller model, electrode, temperature probe, cable, installation method and signal requirements.
- Select pH or ORP mode and configure the temperature-compensation method.
- Scale the isolated 4–20mA output to the required measurement range, then verify it with the receiving system.
- Set the Modbus address and baud rate when RS485 communication is required.
- Configure relay action and release points from the process control requirement, then test both relay outputs before automatic dosing.
- Perform the documented two-point pH calibration with suitable standard solutions, or the one-point ORP calibration with a verified standard.
- Record inspection, cleaning and calibration checks according to the liquid and electrode condition. The manual notes that an electrode efficiency below 80% indicates ageing and should be reviewed.
Frequently Asked Questions
Frequently Asked Questions
Does PH-302 support both pH and ORP?
Yes. The manual documents selectable pH and ORP measurement modes. The electrode and settings determine the active measuring arrangement.
Does PH-302 support RS485 Modbus RTU?
Yes. PH-302 documents RS485 Modbus RTU communication with selectable 9600, 19200 or 38400 baud rates. Confirm the required address and register mapping for the project.
How many analogue outputs does PH-302 provide?
The specification identifies one isolated 4–20mA output with a maximum 500Ω load. Confirm the exact output mapping and supplied variant before ordering.
Which electrode should I choose?
Choose from the liquid, pH or ORP range, temperature, pressure, installation and maintenance conditions. TB84H0, TB84H7W and TB84R1 are compatible options shown on this site, subject to final configuration review.
What should be included in a quotation request?
Provide the liquid, parameter, range, temperature, pressure, installation method, cable length, output and communication requirements, control logic, quantity and destination country.
Compare the pH and ORP controller range, review the electroplating pH monitoring case study, or browse the complete Tenber instrument catalog.
Manuals, Related Products and Request for Quotation
Confirm the PH-302 measuring configuration
Send the liquid, pH or ORP range, temperature, installation, signal, communication and control requirements. Tenber will review the controller and electrode combination before quotation.
Selection flow for PH-302
Start with pH or ORP measurement, then check the complete measuring loop before quotation.
- Define the application and liquid composition.
- Record the normal and maximum value, temperature, pressure and flow conditions.
- Choose the sensor or electrode, installation method, cable and maintenance access together with the controller.
- Confirm the receiving system, including 4–20mA, RS485 Modbus RTU, relay, recorder, PLC or DCS requirements.
- Send the quantity, destination country and current documentation requirement for model review.
Application boundaries
Confirm the electrode, temperature input, analogue output, RS485 Modbus RTU and relay requirements for the supplied variant.
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.