Hanuo HN-015TD-II Transparent Low-Temperature Circulating Bath

Overview

The Hanuo HN-015TD-II Transparent Low-Temperature Circulating Bath is an engineered precision thermal management system designed for laboratories requiring stable, observable, and reproducible temperature control across a wide operational range (0–80 °C). Unlike conventional opaque baths, its triple-side transparent acrylic chamber enables real-time visual monitoring of sample behavior—including color transitions, phase separation, precipitate formation, and fluid dynamics—without compromising thermal integrity or safety. The unit employs a dual-mode thermoelectric compression refrigeration and resistive heating architecture, regulated by a high-resolution PID controller with 0.01 °C display resolution and ±0.05 °C stability under steady-state conditions. Its 15-liter working volume (300 × 250 × 200 mm internal dimensions) supports standard immersion probes, cuvettes, and small-scale reactors while maintaining uniform thermal distribution via an integrated internal circulation pump. This design meets functional requirements for ISO/IEC 17025-accredited calibration labs, USP temperature verification protocols, and ASTM E2251-22 reference bath applications.

Key Features

• Triple-side optically clear acrylic construction for unobstructed visual observation of samples, reagent mixing, and reaction kinetics
• PID-controlled dual-mode thermal regulation (refrigeration + heating) ensuring rapid setpoint acquisition and minimal overshoot
• ±0.05 °C temperature stability at 25 °C ambient, verified per ISO 17025 traceable procedures
• Internal recirculation system with adjustable flow rate to minimize thermal gradients (<0.1 °C deviation across bath volume)
• Large backlit LCD interface displaying both setpoint and real-time measured temperature with 0.01 °C resolution
• Compact desktop footprint (W420 × D320 × H380 mm) optimized for fume hood integration and benchtop space efficiency
• Over-temperature and low-level liquid protection circuits compliant with IEC 61010-1 safety standards

Sample Compatibility & Compliance

The HN-015TD-II accommodates a broad spectrum of sample containers—including quartz and borosilicate glass cuvettes (up to 10 mm pathlength), stainless steel immersion probes, PTFE-coated thermistors, and small-volume reaction vessels (≤500 mL). Its non-corrosive acrylic chamber resists common solvents (e.g., ethanol, acetone, aqueous buffers) and is compatible with deionized water, glycol-water mixtures, and silicone oils (viscosity ≤50 cSt). The bath conforms to key regulatory frameworks for analytical instrumentation: it supports audit-ready operation under FDA 21 CFR Part 11 when paired with validated data logging software; meets temperature uniformity criteria outlined in USP for thermometer calibration; and satisfies the thermal stability prerequisites of ISO 9001-certified QC workflows. Optional NIST-traceable calibration certificates are available upon request.

Software & Data Management

While the HN-015TD-II operates as a standalone analog-digital hybrid instrument, its RS-232 serial port enables bidirectional communication with third-party laboratory information management systems (LIMS) and PC-based data acquisition platforms (e.g., LabVIEW, MATLAB, or custom Python scripts). Users may log temperature profiles at user-defined intervals (1–60 s), generate time-stamped CSV reports, and trigger alarms based on deviation thresholds. For GxP environments, optional firmware upgrades support electronic signature authentication, user access levels (admin/operator), and immutable audit trails compliant with ALCOA+ principles. All firmware updates undergo regression testing against IEC 62304 medical device software standards.

Applications

• Calibration of digital thermometers, RTDs, and thermocouples per ASTM E74-23 and ISO/IEC 17025
• Temperature-dependent spectroscopic measurements (UV-Vis, FTIR, fluorescence) requiring optical access and thermal stability
• Viscosity benchmarking using capillary or rotational viscometers where bath-induced shear must be minimized
• In-situ monitoring of enzymatic reactions, polymerization kinetics, and crystallization studies
• Thermal validation of microfluidic devices and lab-on-chip platforms
• Reference standard stabilization for metrology-grade instruments in national metrology institutes

FAQ

What is the maximum allowable working fluid viscosity for internal circulation?
The internal pump is rated for fluids up to 50 cSt at 25 °C. Silicone oils exceeding this limit require external recirculation loops.
Can the bath operate continuously at 0 °C in ambient conditions above 30 °C?
Yes—its compressor-based cooling system maintains 0 °C setpoint with ≤2 K ambient derating up to 35 °C room temperature.
Is the acrylic chamber resistant to hydrochloric acid or sodium hydroxide solutions?
No. Acrylic is incompatible with strong bases and oxidizing acids. Use only neutral or mildly acidic aqueous media.
Does the unit include a factory calibration certificate?
Standard delivery includes a performance verification report. NIST-traceable calibration documentation is available as an add-on service.
How is temperature uniformity validated across the bath volume?
Uniformity is assessed using three calibrated PT100 probes positioned at center, corner, and mid-depth locations per ISO 17025 Annex A.3.