Tianfeng TF-HX-8A Precision Circulating Water/Oil Bath Chiller

Overview

The Tianfeng TF-HX-8A is a high-stability circulating constant-temperature bath engineered for precision thermal control in analytical, pharmaceutical, and materials science laboratories. It operates on a closed-loop refrigeration and heating system, integrating a hermetic compressor, copper-alloy evaporator and condenser, and a dual-mode circulation pump capable of both internal bath homogenization and external fluid delivery to auxiliary equipment (e.g., viscometers, spectrophotometer jackets, or reaction blocks). The unit maintains temperature setpoints across its full operational range (−10 °C to 99 °C) using a PT100 platinum resistance sensor coupled with microprocessor-driven PID control featuring auto-tuning capability—ensuring minimal thermal overshoot and long-term stability within ±0.1 °C. Its compact footprint (430 × 313 × 797 mm) and 8-liter stainless steel reservoir support integration into benchtop workflows without compromising thermal uniformity or mechanical robustness.

Key Features

• Backlit LCD interface displaying real-time bath temperature, setpoint, heating/cooling status, and power output—enabling intuitive operation and immediate verification of thermal state.
• High-efficiency EBM brushless DC circulation motor (Germany-sourced), delivering consistent flow rates with low acoustic emission (<45 dB(A)) and negligible heat generation—critical for sensitive calorimetric or optical measurements.
• Corrosion-resistant 304 stainless steel tank and top plate, rated for compatibility with water, ethylene glycol/water mixtures, silicone oil, and other common heat-transfer fluids up to 99 °C.
• Dual-circuit design supporting simultaneous internal recirculation (for bath homogeneity) and external delivery (up to 12 L/min at 0.3 bar pressure)—facilitating seamless integration with external instrumentation requiring active temperature regulation.
• Comprehensive safety architecture including dry-run detection (prevents pump damage during low-fluid conditions), overtemperature cutoff (>105 °C hardware limit), and RTD open-circuit alarm—fully compliant with IEC 61010-1:2010 requirements for laboratory electrical equipment.

Sample Compatibility & Compliance

The TF-HX-8A accommodates standard laboratory vessels (up to Ø150 mm diameter) and supports immersion of probes, sensors, and sample holders directly into the bath medium. Its fluid compatibility extends to aqueous solutions, antifreeze blends (e.g., 30% glycol), and synthetic oils—provided viscosity remains below 100 cSt at operating temperature. The unit conforms to ISO/IEC 17025:2017 environmental monitoring prerequisites for temperature-controlled testing environments and meets electromagnetic compatibility (EMC) standards per EN 61326-1:2013. While not certified for GMP production use, its traceable calibration points (via external PT100 reference) and stable thermal profile make it suitable for QC/QA applications aligned with USP , ASTM E2877-22, and ISO 17025-accredited method validation protocols.

Software & Data Management

The TF-HX-8A operates as a standalone instrument with no proprietary software dependency. All parameters—including setpoint, ramp rate, hold time, and circulation mode—are configured via front-panel keypad. For integration into automated lab networks, optional RS485 Modbus RTU communication (add-on module) enables remote parameter readout and basic control through LabVIEW, MATLAB, or SCADA systems. Audit trails are maintained locally via timestamped event logging (power-on, alarm triggers, setpoint changes), supporting GLP documentation practices when paired with external data loggers compliant with FDA 21 CFR Part 11 requirements.

Applications

• Calibration of thermometers, RTDs, and thermocouples against NIST-traceable references.
• Temperature stabilization of UV-Vis spectrophotometer cells, HPLC column ovens, and differential scanning calorimeters (DSC).
• Controlled-rate cooling/heating for polymer crystallization studies and phase transition analysis.
• Thermal preconditioning of reagents and biological samples prior to enzymatic assays or cell culture procedures.
• Supporting ASTM D2857 (viscosity of asphalt binders) and ISO 3104 (petroleum products) test methods requiring precise bath temperature maintenance.

FAQ

What is the maximum allowable viscosity of heat-transfer fluid for external circulation?
Fluids with kinematic viscosity ≤100 cSt at the operating temperature are recommended to ensure adequate flow and thermal response.
Can the unit maintain sub-zero temperatures continuously?
Yes—the compressor-based refrigeration system sustains stable operation down to −10 °C, provided ambient temperature remains ≤30 °C and relative humidity <80% non-condensing.
Is calibration certificate included with shipment?
A factory-issued calibration report (covering three points: 0 °C, 25 °C, and 60 °C) is supplied; NIST-traceable certification is available upon request with additional lead time.
How often does the system require maintenance?
Annual inspection of refrigerant charge, condenser coil cleaning, and verification of PID tuning parameters is advised under continuous operation; no routine oil changes are required for the sealed compressor or EBM motor.
Does the bath support programmable temperature ramps?
No—ramp functionality is not embedded in the base controller; however, external programmable logic controllers (PLCs) or PC-based automation can be interfaced via RS485 Modbus for multi-step thermal profiles.