Jianhu JH-501A Precision Circulating Water Bath

Overview

The Jianhu JH-501A Precision Circulating Water Bath is an engineered thermal management system designed for stable, reproducible temperature control in laboratory and quality assurance settings. Operating on the principle of forced convection via a built-in circulation pump, it maintains uniform thermal distribution across the bath chamber—both internally (within the tank) and externally (through connected apparatus such as viscometers, spectrophotometer cells, or reaction jackets). Its microprocessor-based PID temperature controller delivers setpoint accuracy within ±0.5°C and resolution to 0.1°C over a usable range from ambient +5°C to 100°C—making it suitable for applications requiring precise thermal conditioning without phase transition risks associated with oil-based systems. Constructed entirely from 304 stainless steel (interior and exterior), the unit resists corrosion from aqueous solutions, cleaning agents, and prolonged humid exposure—ensuring long-term dimensional stability and compliance with ISO 17025 environmental preconditioning requirements.

Key Features

• Stainless steel construction (304 grade) for chemical resistance, structural integrity, and ease of decontamination
• Digital microprocessor controller with real-time temperature display and adjustable setpoint precision (0.1°C increments)
• Programmable timer function (1–999 minutes) enabling unattended operation and protocol repeatability
• Integrated dual-mode circulation: internal recirculation for bath homogeneity; external port for closed-loop connection to peripheral equipment
• Over-temperature protection with simultaneous audible alarm and visual LED indicator—automatically cuts heating power upon deviation exceeding safety threshold
• Low thermal mass design ensures rapid heat-up time (<15 min to reach 60°C from 25°C under no-load conditions) and minimal overshoot during stabilization
• Compact footprint (570×270×260 mm) optimized for benchtop integration in regulated QC labs and teaching laboratories

Sample Compatibility & Compliance

The JH-501A accommodates standard laboratory glassware (e.g., beakers up to 1000 mL, cuvettes, calibration standards) and supports immersion-based thermal equilibration of sensors, reference materials, and small-volume samples. Its 11 L working volume and 420×180×150 mm chamber allow vertical sample placement up to 150 mm height. The unit complies with IEC 61010-1:2010 for electrical safety in laboratory equipment and meets essential requirements for use in environments adhering to Good Laboratory Practice (GLP) and ISO/IEC 17025:2017 Clause 6.4 (equipment verification). While not certified to FDA 21 CFR Part 11 out-of-the-box, its digital logging capability (via optional RS232 interface) supports audit-trail implementation when integrated into validated data acquisition workflows.

Software & Data Management

The JH-501A operates autonomously via front-panel controls but includes an RS232 communication port (optional cable and driver available) for integration with PC-based monitoring software. This enables remote setpoint adjustment, real-time temperature streaming, and timestamped data export (CSV format) for traceability in QA documentation. When deployed in regulated environments, users may configure third-party SCADA or LIMS platforms to capture thermal event logs—including start/stop times, deviation alerts, and cumulative run duration—for alignment with internal SOPs and external audit readiness.

Applications

• Calibration of thermometers, RTDs, and thermocouples against NIST-traceable references
• Pre-conditioning of polymer solutions prior to rheological testing (e.g., Brookfield or Anton Paar measurements)
• Thermal equilibration of biological reagents, enzyme assays, and cell culture media
• Supporting ASTM D2196 (viscosity of paints) and ISO 2555 (solution viscosity) test protocols requiring controlled bath temperatures
• Stabilizing optical components during spectral characterization where thermal drift affects wavelength accuracy
• Teaching laboratories: demonstrating thermal equilibrium, heat transfer coefficients, and Arrhenius kinetics

FAQ

Does the JH-501A support external recirculation to jacketed reactors or condensers?
Yes—the unit features dedicated inlet/outlet ports compatible with standard 10 mm ID silicone or fluoropolymer tubing, rated for continuous flow at ≤2 L/min and pressures up to 0.1 MPa.
Can the temperature sensor be calibrated independently?
The PT100 sensor is factory-calibrated and user-accessible for periodic verification using a certified reference thermometer per ISO 17025 Section 6.5; full recalibration requires authorized service center tools.
Is the unit suitable for use with organic solvents?
Not recommended—while the stainless steel chamber resists many aqueous buffers, volatile organic solvents (e.g., acetone, ethanol, chloroform) may degrade seals and compromise pump longevity; use only with water or aqueous salt solutions.
What maintenance intervals are advised for sustained performance?
Biannual inspection of pump impeller, descaling of heater surface (using 5% citric acid solution), and verification of door gasket integrity are recommended under normal usage (≤6 hr/day, 5 days/week).
How is traceability ensured for regulatory submissions?
Each unit ships with a factory calibration certificate (traceable to CNAS-accredited standards); users must perform initial verification and document subsequent checks per their site’s equipment qualification protocol (IQ/OQ/PQ).