Hanuo HNGD-40200-5 High-Low Temperature Circulating Bath

Overview

The Hanuo HNGD-40200-5 is a precision-engineered high-low temperature circulating bath designed for laboratory and pilot-scale applications requiring stable thermal control across an extended operational range. Utilizing a closed-loop refrigeration-heating system with cascade compressor technology and PID-controlled electric heating elements, the unit delivers consistent thermal energy transfer to external equipment (e.g., reactors, viscometers, spectrometers) or internal samples via forced convection. Its −40 °C to +200 °C operating envelope supports cryogenic reaction initiation, polymerization kinetics studies, material curing validation, and high-temperature stability testing—without requiring fluid exchange or auxiliary chillers. The stainless steel 304 bath reservoir ensures chemical resistance and long-term dimensional stability under repeated thermal cycling.

Key Features

• Wide temperature span: Achieves and maintains −40 °C with rapid cooldown (≤60 min from 20 °C to −40 °C) and up to +200 °C with precise overshoot suppression
• Dual-mode circulation architecture: Independent internal bath circulation and externally routed flow (via dual quick-connect ports) enable simultaneous temperature control of multiple devices or closed-loop jacketed systems
• High-stability temperature regulation: ±0.1 °C stability at setpoint (measured at bath sensor location per ASTM E742), supported by a Pt100 Class A immersion probe and adaptive PID algorithm with auto-tuning capability
• Intelligent safety system: Includes over-temperature cutoff, low-level fluid alarm, dry-run protection, refrigerant pressure monitoring, and ground-fault circuit interruption (GFCI)
• Robust mechanical design: Integrated centrifugal pump with ceramic shaft and graphite bearings; corrosion-resistant 304 stainless steel tank; reinforced insulation layer minimizing ambient heat load
• Front-panel digital interface: 4.3-inch TFT LCD with intuitive menu navigation, real-time trend graphing (last 72 h), and user-configurable alarm thresholds

Sample Compatibility & Compliance

The HNGD-40200-5 accommodates a broad spectrum of heat-transfer fluids—including deionized water, 50/50 ethylene glycol/water blends, and methyl silicone oils (up to 350 cSt)—enabling optimization for viscosity, flash point, and thermal conductivity requirements. Its sealed circulation path prevents evaporation loss and oxidation during prolonged operation. The unit complies with IEC 61010-1:2010 for electrical safety in laboratory equipment and meets CE marking requirements for electromagnetic compatibility (EMC Directive 2014/30/EU). While not certified for hazardous area use (ATEX/IECEx), it is suitable for general-purpose laboratories operating under ISO/IEC 17025-accredited quality management systems. Fluid containment integrity adheres to ISO 13849-1 PL e functional safety principles for critical shutdown functions.

Software & Data Management

Standard RS485 Modbus RTU and optional USB-to-serial interfaces support integration into centralized lab automation platforms. Hanuo’s optional LabLink™ PC software enables remote setpoint scheduling, real-time data logging (sample interval configurable from 1 s to 1 h), CSV export, and deviation reporting aligned with GLP documentation standards. Audit trail functionality records operator login, parameter changes, alarm events, and calibration actions—supporting compliance with FDA 21 CFR Part 11 when deployed with validated electronic signatures and time-stamped logs. All firmware updates are delivered via signed binary packages to ensure traceable version control.

Applications

• Chemical synthesis: Precise temperature ramping and hold profiles for exothermic/endothermic reactions in jacketed glass reactors
• Materials testing: Thermal aging of polymers, adhesives, and composites per ASTM D3045 and ISO 2578
• Pharmaceutical development: Dissolution apparatus temperature verification (USP ), stability chamber qualification (ICH Q5C), and excipient compatibility screening
• Instrument calibration: Providing traceable thermal references for thermocouple and RTD calibrators, DSC, and TGA systems
• Electronics reliability: Thermal shock simulation for PCB solder joint evaluation (JEDEC JESD22-A104)
• Biotechnology: Controlled thawing of cryopreserved cell lines and enzymatic activity assays requiring sub-zero incubation

FAQ

What fluids are compatible with the HNGD-40200-5 at −40 °C?
Ethylene glycol/water (30/70 v/v) and low-viscosity silicone oils (e.g., Dow Corning® 200 Fluid 0.65 cSt) are validated for continuous operation at −40 °C. Avoid aqueous solutions with high salt content due to freezing-point elevation and corrosion risk.
Can the unit maintain ±0.1 °C stability while supplying external flow?
Yes—stability specification holds under full external load (15 L/min at 3.5 m head) provided the connected system’s thermal mass and insulation meet standard laboratory practice guidelines (e.g., ASHRAE RP-1142).
Is external PT100 input supported for process temperature feedback control?
The unit includes one analog input channel (0–10 V or 4–20 mA) for external sensor integration, enabling cascade control mode where the bath regulates based on process temperature rather than bath temperature.
What maintenance intervals are recommended for optimal performance?
Refrigerant oil inspection every 12 months; condenser coil cleaning quarterly in dusty environments; annual verification of temperature sensor accuracy against NIST-traceable reference standards.
Does the system support protocol-based temperature programming (e.g., ramps, holds, cycles)?
Yes—up to 10 programmable segments (linear ramps, dwell periods, step changes) can be stored locally and executed autonomously without PC connection.