The Great Wall HX-2505G Precision Temperature Circulator

Overview

The Great Wall HX-2505G Precision Temperature Circulator is an engineered thermal management system designed for laboratory-scale temperature control of external devices and reaction vessels. It operates on a closed-loop liquid circulation principle, utilizing a dual-impeller centrifugal pump and PID-regulated heating/cooling to maintain precise setpoint temperatures across a broad operational range (−25 °C to 200 °C). Unlike simple immersion baths, the HX-2505G delivers stable thermal energy transfer to external equipment—including electrophoresis units, rheometers, viscometers, probe-based analytical instruments, and jacketed reactors—enabling accurate kinetic studies, calibration traceability, and process validation under controlled thermal conditions. Its integrated refrigeration circuit employs R404A, a zeotropic blend compliant with industrial low-GWP refrigerant standards for non-automotive applications, while its stainless-steel-compatible fluid path ensures compatibility with common heat-transfer media such as water, ethanol–water mixtures, silicone oils, and glycol solutions.

Key Features

• PID-controlled temperature regulation with ±0.2 °C stability and 0.1 °C digital resolution, ensuring repeatability in method-critical workflows.
• Dual-impeller circulation pump with self-priming capability, enabling reliable flow delivery to both open-bath and pressurized closed-loop systems (≤0.2 bar max backpressure).
• Uniform bath temperature distribution achieved via internal impeller-driven agitation, minimizing radial and vertical thermal gradients within the 6 L reservoir.
• Modular thermal architecture: independent heating (1.1 kW resistive) and cooling circuits (variable-capacity compressor) allow simultaneous or selective operation without cross-interference.
• Robust mechanical design featuring cold-rolled steel housing with electrostatic epoxy coating, IP20 ingress protection, and CE-compliant electrical safety architecture.
• RS485 serial interface for integration into centralized lab automation networks, supporting Modbus RTU protocol for remote setpoint adjustment and status monitoring.

Sample Compatibility & Compliance

The HX-2505G supports thermal conditioning of diverse sample containers and instrumentation interfaces, including standard 153 mm × 60 mm bath openings and M16×1 external coupling ports compatible with ISO 228-1 thread standards. It meets essential safety and electromagnetic compatibility requirements per IEC 61010-1 (Laboratory Equipment Safety) and IEC 61326-1 (EMC for Measurement and Control Devices). While not certified to UL or CSA standards out-of-box, its design aligns with foundational principles of GLP-compliant thermal validation—particularly when used in conjunction with NIST-traceable PT100 probes for independent temperature verification. The unit complies with RoHS Directive 2011/65/EU regarding hazardous substance restrictions and conforms to EU F-Gas Regulation (No. 517/2014) for refrigerant handling documentation.

Software & Data Management

The HX-2505G operates autonomously via front-panel keypad navigation and real-time LED display; no proprietary software is required for basic function. For advanced integration, the RS485 port enables connection to third-party SCADA or LIMS platforms using standard Modbus RTU commands (e.g., function codes 03h/06h for reading/writing temperature setpoints and status registers). Users may log time-stamped temperature data via external DAQ systems, supporting audit-ready records aligned with FDA 21 CFR Part 11 principles when paired with appropriate electronic signature and audit trail configurations. Firmware updates are performed manually via USB-to-RS485 adapter; version history and calibration logs are stored internally with timestamped metadata.

Applications

• Temperature-controlled electrophoresis: maintaining consistent buffer viscosity and migration kinetics during DNA/RNA separation.
• Viscometry and rheology: stabilizing sample temperature in rotational or capillary viscometers per ASTM D445 and ISO 3104 protocols.
• Calibration of temperature-sensitive sensors: providing stable reference environments for thermistor, RTD, and thermocouple verification against ISO/IEC 17025-accredited standards.
• Reaction calorimetry support: supplying regulated coolant to jacketed reactors during exothermic synthesis or polymerization studies.
• Materials testing: conditioning polymer samples prior to tensile, impact, or DMA analysis per ASTM D638 and ISO 527.
• QC/QA laboratories: sustaining temperature uniformity in stability chambers, dissolution apparatus baths, and reference material storage.

FAQ

What types of heat-transfer fluids are compatible with the HX-2505G?

Water, 30–50% aqueous ethylene glycol, silicone oils (up to 200 °C), and ethanol–water mixtures are commonly used. Avoid chlorinated solvents or highly viscous fluids exceeding 100 cSt at operating temperature.
Can the unit operate continuously at extreme setpoints (e.g., −25 °C or 200 °C)?

Yes—continuous operation is supported across the full range, though sustained use near thermal limits may reduce compressor lifespan. Recommended duty cycle: ≤85% of maximum refrigeration capacity at sub-zero temperatures.
Is the bath reservoir drainable for fluid replacement or maintenance?

Yes—a bottom-mounted quick-release valve allows complete fluid evacuation without disassembly. Reservoir cleaning is facilitated by the removable lid and smooth-welded interior surfaces.
Does the HX-2505G support external temperature feedback control?

No—the unit relies on internal Pt100 sensor feedback only. For process-critical applications requiring external probe input, a programmable external controller (e.g., Eurotherm 2408) must be interfaced via analog 0–10 V or 4–20 mA signals.
What is the expected service life of the R404A refrigeration system under normal lab use?

With proper ventilation, ambient humidity control (<70% RH), and annual preventive maintenance (oil inspection, filter-drier replacement), the sealed compressor system typically exceeds 12,000 operating hours before major service intervention.