CZGY HH-101A Low-Temperature Constant-Temperature Water Bath

Overview

The CZGY HH-101A Low-Temperature Constant-Temperature Water Bath is an engineered thermal control platform designed for precise, stable temperature regulation across a broad operational range (0–100 °C). It employs dual-mode thermoregulation—integrated resistive heating and vapor-compression refrigeration—to maintain setpoint accuracy without manual intervention. The system operates on the principle of active heat exchange: the immersion bath medium (deionized water or low-viscosity silicone oil) serves as both thermal mass and transfer medium, while a high-efficiency centrifugal circulation pump ensures uniform temperature distribution via internal recirculation or external connection to auxiliary equipment (e.g., spectrophotometer jackets, condenser coils, or reaction blocks). Its stainless-steel inner tank and powder-coated cold-rolled steel exterior provide long-term corrosion resistance in humid laboratory environments. Designed for continuous-duty operation under ISO/IEC 17025-aligned laboratory conditions, the HH-101A meets baseline mechanical and electrical safety requirements per IEC 61010-1 and supports GLP-compliant workflows through programmable timing and digital setpoint logging.

Key Features

• Intelligent PID temperature controller with dual-stage auto-tuning (ATU) capability—enables adaptive parameter optimization for varying load conditions and ambient fluctuations
• Digital display interface with 0.1 °C resolution; real-time monitoring of actual and setpoint temperatures
• Configurable refrigeration engagement logic: compressor activation threshold (AFL = 10.0 °C default), deactivation threshold (AFH = 35.0 °C default), and hysteresis band (FAL = 1.0 °C) to minimize thermal cycling and extend compressor service life
• Compressor restart delay protection (Alt = 140 s default) prevents high-pressure start-up damage per ASHRAE refrigeration safety guidelines
• Electronic timer function supports unattended operation for extended protocols (e.g., enzymatic incubation, solvent evaporation, or accelerated stability testing)
• Adjustable sensor offset calibration (Sc: ±19.9 °C range) allows traceable correction against NIST-traceable reference thermometers
• Three-level parameter lock (LcK: 0–2) secures configuration integrity during multi-user deployment

Sample Compatibility & Compliance

The HH-101A accommodates standard laboratory glassware—including round-bottom flasks (up to 2 L), condenser assemblies, chromatography columns, and sample racks—within its 300 × 240 × 180 mm usable opening. Its 12.9 L working volume supports immersion of multiple vessels simultaneously while maintaining thermal homogeneity (±0.5 °C stability at 25 °C, measured per ASTM E2234). The unit complies with general-purpose laboratory equipment standards under GB/T 28026.1–2011 (Chinese national standard for thermostatic baths) and incorporates electrical insulation and grounding provisions aligned with IEC 61010-1:2010. While not certified to UL or CE for export markets, its design architecture permits third-party verification for ISO 9001 quality system integration and supports audit-ready documentation when paired with external data loggers.

Software & Data Management

The HH-101A operates via embedded firmware without proprietary PC software. All operational parameters—including setpoint, timer duration, SC offset, AFL/AFH thresholds, and PID coefficients (P = 10 °C, I = 120 s, D = 30 s)—are configured directly via front-panel keypad navigation. The controller stores no historical temperature logs internally; however, analog voltage output (0–5 V or 4–20 mA, optional upon request) enables connection to external DAQ systems compliant with FDA 21 CFR Part 11 for electronic record retention. For laboratories requiring full audit trails, integration with LabArchives, LabTrove, or custom SCADA platforms is achievable using RS-485 Modbus RTU protocol (add-on module required). Calibration records, maintenance logs, and deviation reports must be maintained manually per GLP Annex 11 principles.

Applications

• Controlled-rate cooling/heating of chemical reaction mixtures prior to GC/HPLC injection
• Temperature stabilization of optical components (e.g., CCD detectors, interferometer arms) during spectroscopic measurements
• Pre-conditioning of polymer samples for tensile or rheological testing per ASTM D638 and ISO 527
• Enzyme kinetics assays requiring strict thermal control between 4 °C (cold storage simulation) and 65 °C (denaturation studies)
• Accelerated stability testing of pharmaceutical formulations per ICH Q1A(R2), using bracketed temperature profiles (e.g., 40 °C/75% RH equivalents via indirect jacket control)
• Calibration of liquid-in-glass thermometers and RTD probes against reference standards

FAQ

What is the minimum operating temperature, and does it require antifreeze solution?
The HH-101A achieves 0 °C using pure water; no antifreeze is required. Below 5 °C, use deionized water to prevent mineral precipitation and ensure consistent heat transfer.
Can the unit maintain temperature during power interruption?
No battery backup is included. Upon power loss, thermal drift follows Newtonian cooling curves—typical decay rate is ~0.8 °C/min at 25 °C ambient (measured with 10 L water load).
Is external circulation compatible with all tubing materials?
Yes—standard silicone, Viton®, or PTFE tubing (ID ≥ 6 mm) may be used. Avoid PVC below 10 °C due to embrittlement risk.
How often should the refrigerant system be serviced?
Under normal lab use (≤8 hrs/day), compressor oil and refrigerant charge remain stable for ≥5 years. Annual visual inspection of condenser coil cleanliness and evaporator frost pattern is recommended.
Does the unit support remote start/stop via digital I/O?
Not natively. Optional RS-485 Modbus RTU interface (part number HH-COM-01) enables external PLC or BMS integration for automated sequencing.