SUP-PH6.8 pH/ORP meter—Precision Online pH & ORP Monitoring for Industrial Process Control
The PH6.8 is a panel-mount online pH/ORP controller engineered for continuous monitoring in water treatment, chemical processing, food & beverage, and HVAC systems. Featuring a 2.8-inch monochrome LCD, isolated 4–20 mA analog output, and RS485 Modbus-RTU communication, it delivers real-time measurement data directly to your control room or DCS/SCADA system. With ±0.02 pH accuracy and dual-relay alarm outputs, the PH6.8 ensures reliable process control and regulatory compliance in demanding industrial environments.
The PH6.8 is a panel-mount online pH/ORP controller engineered for continuous monitoring in water treatment, chemical processing, food & beverage, and HVAC systems. Featuring a 2.8-inch monochrome LCD, isolated 4–20 mA analog output, and RS485 Modbus-RTU communication, it delivers real-time measurement data directly to your control room or DCS/SCADA system. With ±0.02 pH accuracy and dual-relay alarm outputs, the PH6.8 ensures reliable process control and regulatory compliance in demanding industrial environments.
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.
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
Screen size
2.8 inch monochrome LCD with a resolution of 128*64
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 PH6.8 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 PH6.8 connect to a SCADA or PLC system?
Yes. The PH6.8 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 PH6.8?
The PH6.8 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 PH6.8 suitable for outdoor installation?
The PH6.8 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 PH6.8?
The PH6.8 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 PH6.8 support Modbus RTU protocol?
Yes. The PH6.8 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 PH6.8 typically used in?
The PH6.8 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.
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