JENCO 6309PDT Industrial Online pH / Dissolved Oxygen / Temperature Analyzer and Controller

Overview

The JENCO 6309PDT is a single-channel, industrial-grade online analyzer engineered for continuous, simultaneous monitoring and control of pH, dissolved oxygen (DO), and temperature in demanding process environments—including wastewater treatment, aquaculture, bioreactor operations, and municipal water systems. Built on a microprocessor-based architecture with real-time digital signal processing, the 6309PDT employs potentiometric measurement for pH (using high-impedance differential amplification), polarographic or galvanic sensing for dissolved oxygen (depending on electrode configuration), and precision thermistor-based temperature compensation (22 kΩ @ 25 °C). Its design conforms to IEC 61000-6-2 (EMC immunity) and IEC 61000-6-4 (EMC emissions) standards, ensuring stable operation in electrically noisy industrial settings. The instrument supports automatic temperature, salinity, and barometric pressure compensation—critical for accurate DO reporting across variable environmental conditions—and integrates seamlessly into PLC-controlled or SCADA-monitored infrastructure via isolated analog output and relay logic.

Key Features

• Triple-parameter measurement: Simultaneous real-time acquisition of pH (–2.00 to 16.00), DO (0.00–60.00 ppm / 0.0–500.0 % saturation), and temperature (–10.0 to 120.0 °C)
• High-impedance pH input (>10¹³ Ω) with auto-buffer recognition for standard calibration using either NIST-traceable (4.01/7.00/10.01) or DIN-compliant (4.00/6.86/9.18) buffer sets
• Configurable electrode diagnostics: Automatic zero-point and slope compensation (±100 mV / ±30 %) with live status feedback
• Full environmental compensation: Salinity (0.0–49.9 ppt), temperature (0.0–80.0 °C), and atmospheric pressure (600–1100 mbar)
• Isolated, reversible 4–20 mA analog output with 500 VDC isolation rating and ≤500 Ω max load impedance
• Two-pole SPDT relay output supporting ON/OFF control logic with 2.5 A / 230 VAC switching capacity
• IP65-rated front panel enclosure with audible keypress feedback and four-digit password protection for parameter lockout
• 1/4 DIN form factor (96 × 96 × 148 mm) with standardized 92 × 92 mm cutout for panel integration

Sample Compatibility & Compliance

The 6309PDT is optimized for aqueous process streams ranging from clean potable water to highly turbid or particulate-laden effluents. Compatible electrodes—including the IP-600 series (e.g., IP-600-1 for sludge-rich wastewater; IP-600-10/15 for general secondary treatment) and OXYSENS 120 (optimized for low-flow aquaculture and activated sludge tanks)—are designed for long-term immersion and fouling resistance. The analyzer complies with ISO 5667-14 (water quality sampling), ASTM D1293 (pH of water), and ASTM D888 (dissolved oxygen in water), and supports audit-ready operation under GLP and GMP frameworks when paired with optional data logging accessories. Its relay control logic meets IEC 61508 SIL 1 requirements for basic safety-related functions in non-critical process loops.

Software & Data Management

While the 6309PDT operates as a standalone controller without embedded PC software, its analog output enables direct integration with third-party SCADA platforms (e.g., Ignition, Siemens Desigo, or Schneider EcoStruxure) for historical trend analysis and alarm management. All calibration events, relay state changes, and sensor diagnostics are timestamped and stored in non-volatile memory for up to 30 days. Configuration parameters—including buffer selection, compensation ranges, and output scaling—are retained during power loss. For regulatory environments requiring electronic record integrity, the device supports 21 CFR Part 11–compliant external data acquisition when used with validated OPC UA or Modbus TCP gateways and time-synchronized historian servers.

Applications

• Wastewater treatment plants: pH neutralization control in equalization basins; DO optimization in aerobic digesters and activated sludge tanks
• Aquaculture facilities: Real-time DO monitoring in recirculating aquaculture systems (RAS) with automated aeration response
• Food & beverage processing: Sanitary rinse water pH verification and CIP cycle temperature validation
• Power plant cooling towers: Corrosion-inhibiting pH setpoint maintenance and dissolved oxygen scavenger dosing control
• Municipal drinking water: Post-chlorination pH stabilization and distribution system temperature profiling

FAQ

Does the 6309PDT support automatic temperature compensation for both pH and DO measurements?

Yes—temperature is measured continuously via integrated 22 kΩ thermistor and applied automatically to pH slope correction and DO solubility calculations per the Winkler and APHA standard algorithms.
Can the 4–20 mA output be assigned to individual parameters (e.g., pH only or DO only)?

Yes—the output channel is fully configurable via front-panel menu to represent any one of the three measured parameters, with user-defined zero/span scaling.
What is the maximum cable length supported between the 6309PDT and a remote DO or pH electrode?

For optimal signal integrity, JENCO recommends ≤15 m for shielded, twisted-pair cables; longer runs require signal conditioning or local transmitter modules.
Is the relay output programmable for proportional-integral (PI) control?

No—the relay operates in hysteresis-based ON/OFF mode only; for modulating control, use the 4–20 mA output with an external PID controller.
Are calibration logs exportable via USB or serial interface?

No—the unit lacks native USB or RS-232 ports; calibration history is viewable on-screen and retained internally but requires manual transcription or SCADA-level extraction via analog trending.