Hanuo HNJD-0505L Magnetic Stirring Constant-Temperature Water Bath Circulator

Overview

The Hanuo HNJD-0505L Magnetic Stirring Constant-Temperature Water Bath Circulator integrates precise temperature control, active magnetic stirring, and dual-mode fluid circulation into a single compact benchtop platform. Unlike conventional hotplate magnetic stirrers—where heating is applied directly to the vessel base—the HNJD-0505L employs indirect water-bath thermal coupling, delivering superior temperature uniformity, reduced thermal gradients, and enhanced reproducibility across reaction volumes. Its thermoelectric refrigeration and resistive heating system enables stable operation from −5 °C to 100 °C, making it suitable for both low-temperature kinetic studies and high-temperature synthesis protocols. The unit operates on the principle of forced convection heat transfer combined with synchronous permanent-magnet rotation, ensuring homogeneous thermal and mechanical conditions within sealed or open vessels without external drive shafts or seals.

Key Features

• Integrated magnetic stirring mechanism with corrosion-resistant PTFE-coated stir bar, synchronized to the bath’s thermal environment—eliminating need for overhead mechanical stirrers or feedthroughs
• Microprocessor-based PID temperature controller with real-time digital display, ±0.1 °C stability over full operating range (−5 to 100 °C)
• Dual-function circulation pump supporting internal recirculation (for bath homogeneity) and external loop delivery (up to 6 L/min at 0.3 bar head pressure) for jacketed reactors or auxiliary cooling/heating systems
• Hermetically sealed, high-efficiency compressor paired with optimized finned evaporator for rapid cooldown (<15 min from 25 °C to 0 °C), minimizing experimental downtime
• 5 L stainless steel bath chamber with polished interior, drain valve, and splash-resistant lid; compatible with standard laboratory glassware up to 500 mL capacity
• Over-temperature, dry-run, and compressor overload protection circuits compliant with IEC 61010-1 safety standards

Sample Compatibility & Compliance

The HNJD-0505L supports a wide range of sample containers—including round-bottom flasks (with optional clamping adapters), beakers, crystallization dishes, and custom jacketed cells—without compromising thermal integrity or stirring efficiency. Its open-bath design facilitates easy access and visual monitoring during extended reactions. All wetted components meet USP Class VI biocompatibility requirements for non-leaching materials. While not certified for GMP manufacturing environments, the instrument satisfies key validation prerequisites for GLP-compliant laboratories: traceable temperature calibration (NIST-traceable reference sensor included), programmable ramp/soak profiles, and audit-ready operational logs when used with optional RS232/USB data export. It conforms to ISO 17025-recommended practices for temperature-controlled equipment verification and aligns with ASTM E2877-22 guidelines for performance testing of laboratory thermostatic baths.

Software & Data Management

The HNJD-0505L includes embedded firmware supporting time-stamped temperature logging at user-selectable intervals (1–60 sec), with data export via USB flash drive or serial interface (RS232). Optional PC software (HanuoLab Suite v3.2) enables remote parameter setting, multi-step temperature programming, real-time graphing, and CSV export compatible with LIMS platforms. All logged data include metadata: date/time stamp, setpoint, actual bath temperature, stirring speed (RPM), and error flags. The system supports 21 CFR Part 11–compliant workflows when deployed with validated software configuration and user-access controls—though native electronic signature capability requires third-party integration.

Applications

• Controlled-rate crystallization and polymorph screening in pharmaceutical development
• Enzyme kinetics assays requiring strict thermal regulation and homogeneous mixing (e.g., Michaelis-Menten studies)
• Calibration of thermocouples, RTDs, and infrared sensors against a stable, stirred thermal reference
• Preparation of temperature-sensitive reagents (e.g., Grignard solutions, organolithium compounds) under inert atmosphere using three-neck flask configurations
• Accelerated stability testing per ICH Q1A(R3) guidelines, where consistent thermal exposure and agitation simulate long-term storage conditions
• Support of electrochemical cells requiring isothermal electrolyte conditioning and mass transport enhancement

FAQ

Can the HNJD-0505L operate continuously at −5 °C?
Yes—its sealed refrigeration circuit and insulated bath housing support uninterrupted operation at minimum setpoint, provided ambient temperature remains ≤30 °C and relative humidity <80% RH.
Is external circulation compatible with silicone oil or ethylene glycol/water mixtures?
Yes, the pump and wetted path are rated for common heat-transfer fluids including 50/50 ethylene glycol/water (up to 100 °C) and silicone oils (up to 200 °C); however, viscosity >50 cSt may reduce flow rate and require periodic filter inspection.
Does the unit include a calibration certificate?
Each unit ships with a factory-issued calibration report referencing NIST-traceable standards for temperature accuracy at three points (0 °C, 25 °C, 70 °C); full ISO/IEC 17025 certification is available upon request as a paid service.
What maintenance is required for long-term reliability?
Biannual inspection of condenser coil cleanliness, annual refrigerant pressure check, and quarterly cleaning of bath chamber with mild detergent—no consumables or scheduled part replacements are specified in the maintenance manual.
Can stirring speed be independently adjusted from temperature setpoint?
Yes—stirring RPM is controlled via dedicated rotary encoder (range: 0–1200 rpm), fully decoupled from thermal parameters and retained across power cycles.