SUP-PH6.5 pH/ORP meter—Precision Online pH & ORP Monitoring for Industrial Process Control

• Introduction

SUP-PH6.5 Online pH meter is a multivariable analyzer used for measuring/controlling the pH and ORP with different temperature. The function is switchable on the device itself. Depending on the measured variable, combination electrodes (e. g. pH sensors) or split versions (glass electrodes with a separate reference electrode) can be readily connected.

The pH 6.5 online pH meters are highly accurate and reliable, with a measurement range that typically ranges from pH 0 to pH 14. This means they can provide precise measurements even in the most demanding industrial applications.

Supmea pH 6.5 online pH meters are designed for continuous monitoring, meaning that they can provide real-time pH readings without the need for manual measurements. This makes them ideal for use in applications where pH levels can fluctuate rapidly, such as in chemical processing, wastewater treatment, and food and beverage production.

pH 6.5 online pH meters are easy to install and maintain, with a simple design that requires minimal calibration and maintenance. They are also designed to withstand harsh environmental conditions, such as high temperatures and corrosive chemicals, making them suitable for use in various industrial settings.

In terms of applications, the pH 6.5 online pH meters are commonly used in industrial settings where pH control is critical, such as in chemical processing plants, water treatment plants, and food and beverage production facilities. They are often used to monitor the pH of chemical solutions, wastewater streams, and food and beverage products to ensure that they meet specific pH requirements.

Overall, Supmea pH 6.5 online pH meters offer a highly accurate, reliable, and continuous solution for pH measurement in a wide range of industrial applications. Their ability to provide real-time pH readings makes them essential for maintaining optimal pH levels and ensuring product quality and safety.

• Key Features

High-Accuracy pH & ORP Measurement

Achieves ±0.02 pH accuracy across a full 0.00–14.00 pH range, with ORP measurement spanning −2000 to +2000 mV (±1 mV in the ±1000 mV core range). Ideal for tight process control in chemical dosing and water quality management.

Isolated 4–20 mA Analog Output

Fully isolated current output (max loop resistance 750 Ω, ±0.2% FS) eliminates ground loops and signal interference, ensuring reliable integration with PLCs, DCS, and data loggers.

RS485 Modbus-RTU Communication

Isolated RS485 serial interface supports Modbus-RTU protocol, allowing seamless connectivity to SCADA systems, HMI panels, and building automation networks. Configurable baud rate (2400–38400 bps) and address (1–247).

Dual-Channel Relay Alarm Control

Two independent relay outputs (AC 250 V / 3 A) with configurable high/low setpoints and hysteresis enable direct pump, valve, or chemical dosing pump control without additional I/O modules.

Automatic & Manual Temperature Compensation

Supports NTC 10K, Pt1000, and Pt100 temperature probes for automatic temperature compensation (ATC) across −10 to 130 °C. Manual temperature entry (−10 to 130 °C) available for applications without a temperature sensor.

Panel-Mount Design with IP5X Protection

Compact 92.5 × 92.5 mm cutout panel-mount form factor (DIN-style) with IP5X dust protection. Compatible with standard instrument cabinets and control panels. Installation panel thickness: 1.5–13 mm.

Wide Power Supply Compatibility

Accepts AC 220 V ±10% (50/60 Hz), AC 110 V ±10%, or DC 24 V ±10%, covering global power standards without additional power converters.

2.8-Inch Backlit LCD Display

128×64 monochrome LCD with adjustable backlight displays real-time pH/ORP value, temperature, output current, and alarm status simultaneously. Bilingual menu (English/Chinese) for global deployment.

• Specification

• Application

Water & Wastewater Treatment    

Continuously monitor influent and effluent pH/ORP levels in municipal water treatment plants, industrial wastewater systems, and effluent neutralization tanks. Relay outputs enable direct control of acid/alkali dosing pumps to maintain process pH within regulatory limits.

Chemical Processing    

Maintain precise pH control in reaction vessels, neutralization systems, and chemical blending processes. The ±0.02 pH accuracy and 4–20 mA output allow tight integration with DCS systems for automated chemical dosing.

HVAC & Cooling Towers    

Control water chemistry in cooling water circuits and HVAC systems to prevent scale formation and corrosion. ORP monitoring enables effective biocide dosing for Legionella control and water hygiene management.

Swimming Pools & Aquaculture    

Real-time pH and ORP monitoring for swimming pool disinfection control (chlorine/ozone dosing) and aquaculture pond water quality management. Adjustable alarm setpoints protect livestock and ensure swimmer safety.

Irrigation & Agriculture    

Monitor fertigation solution pH in hydroponic systems and greenhouse irrigation networks to optimize nutrient uptake and prevent root damage. Compatible with standard agricultural PLC/RTU systems via Modbus-RTU.

Power Generation    

Control boiler feed water, cooling water, and condensate pH to prevent corrosion in thermal power plants and industrial boiler systems. Wide power supply compatibility (AC 110/220 V or DC 24 V) suits diverse plant electrical standards.

• Choose pH electrode

Offers a full range of ph electrodes for measuring different media. Such as sewage, pure water, drinking water etc.

• FAQ

Q：What type of pH electrode is compatible with this controller?    

The PH6.5 is compatible with standard glass composite pH electrodes with BNC or S7 connectors. It supports both pH and ORP (redox) electrodes. For temperature compensation, NTC 10K, Pt1000, and Pt100 probes are supported.

Q：Can the PH6.5 connect to a SCADA or PLC system?    

Yes. The PH6.5 provides two integration paths:

(1) an isolated 4–20 mA analog output compatible with any standard PLC analog input card, and

(2) an isolated RS485 Modbus-RTU serial interface for direct connection to SCADA, DCS, HMI, or building management systems.

Q：What is the calibration procedure for the PH6.5?    

The PH6.5 supports 2-point and 3-point pH calibration using standard buffer solutions (e.g., pH 4.00, 6.86, 9.18). ORP calibration uses 86 mV and 256 mV standard solutions. The controller stores the last two calibration records for traceability. A HOLD mode freezes the analog output during calibration to prevent false alarms.

Q：Is the PH6.5 suitable for outdoor installation?    

The PH6.5 is rated IP5X (dust-protected) and is designed for indoor panel mounting. For outdoor or harsh environment applications, please house the controller in a weatherproof enclosure (IP65 or higher). Contact us for customized enclosure solutions.

Q：What is the power consumption of the PH6.5?    

The PH6.5 requires a minimum input power of 6 W. It accepts AC 220 V ±10% (50/60 Hz), AC 110 V ±10%, or DC 24 V ±10%, making it compatible with global electrical standards.

Q：Does the PH6.5 support Modbus RTU protocol?    

Yes. The PH6.5 features an isolated RS485 interface supporting the Modbus-RTU protocol with function code 03 (read holding registers). Register addresses are provided for pH value, ORP value, temperature, and sensor voltage. Configurable baud rates: 2400, 4800, 9600, 19200, and 38400 bps.

Q：What industries is the PH6.5 typically used in?    

The PH6.5 is widely used in water and wastewater treatment, chemical processing, food and beverage production, HVAC cooling water systems, pharmaceutical manufacturing, swimming pools and aquaculture, irrigation and hydroponics, and power generation. Its combination of precise pH/ORP measurement, relay control outputs, and digital communication makes it suitable for any application requiring continuous online pH monitoring.