Yiheng BWS Series Dual-Function Constant-Temperature Water Bath & Circulating Water Bath

Overview

The Yiheng BWS Series Dual-Function Constant-Temperature Water Bath & Circulating Water Bath is engineered for precision thermal control in routine laboratory workflows requiring stable, uniform heating or temperature maintenance across diverse sample formats. Unlike conventional single-mode water baths, this instrument integrates two operational configurations within a unified chassis: as a static water bath for immersion-based sample equilibration and as a circulating water bath capable of delivering consistent thermal energy to external devices—such as viscometers, reaction blocks, or analytical detectors—via integrated pump-driven fluid circulation. Its core thermal regulation system employs PID-controlled resistive heating elements combined with high-stability Pt100 temperature sensors, ensuring ±0.1 °C temperature stability over extended operation cycles. The unit operates within a standard ambient-to-99.9 °C working range, making it suitable for applications ranging from enzyme incubation and solubility testing to calibration of temperature-sensitive instrumentation.

Key Features

• Integrated dual-mode design: switch seamlessly between static water bath and forced-circulation modes without hardware modification
• One-piece deep-drawn 304 stainless steel inner tank—resistant to corrosion, easy to clean, and compatible with aqueous and mild chemical solutions
• High-resolution LCD display showing real-time setpoint, actual temperature, timer status, and system alerts on a single screen
• Intuitive menu-driven interface with programmable timer (0–999 minutes) and optional multi-stage temperature ramping via add-on controller
• Dry-run protection circuit automatically de-energizes the heater upon low-water detection; manual reset required to prevent unintended restart after refill
• Independent mechanical over-temperature cut-off (adjustable up to 105 °C) provides redundant safety layer beyond electronic PID control
• Modular accessory support including adjustable beaker racks, conical flask holders, stainless steel mesh platforms, and optional angular or transparent acrylic lids
• ABS polymer outer housing—chemically resistant to common lab acids, bases, and solvents; impact-resistant and ergonomically contoured

Sample Compatibility & Compliance

The BWS series accommodates a broad spectrum of sample containers—including glass beakers (50–2000 mL), test tubes, culture flasks, and custom jigs—via its configurable rack system. The flat-bottomed tank geometry ensures even heat distribution, minimizing thermal gradients that could compromise assay reproducibility. All models comply with IEC 61010-1:2010 safety standards for electrical equipment used in laboratory environments. Dry-run and over-temperature safeguards align with GLP requirements for documented thermal process integrity. While not certified for sterile applications, the seamless stainless steel interior supports validated cleaning protocols under ISO 14644-1 Class 7 cleanroom practices when deployed in controlled environments.

Software & Data Management

Standard operation requires no external software—the embedded firmware handles all thermal control logic, timing, and alarm management locally. For laboratories implementing digital audit trails, the optional multi-stage programmable controller enables export of temperature logs (timestamped, CSV-formatted) via USB port. These records include setpoint history, actual temperature readings at 10-second intervals, and event flags for alarms or manual resets—supporting compliance with FDA 21 CFR Part 11 where electronic signatures and data integrity controls are implemented at the institutional level. No cloud connectivity or remote monitoring is provided; all data remains resident on the device or exported media.

Applications

• Biological sample warming prior to analysis (e.g., serum, cell suspensions, PCR reagents)
• Calibration of thermometers, RTDs, and thermocouples against NIST-traceable references
• Accelerated stability testing per ICH Q1A(R2) guidelines using controlled thermal exposure
• Supporting viscosity measurements by maintaining constant bath temperature for rotational rheometers
• Dissolution testing in pharmaceutical QA/QC labs per USP <711> requirements
• Enzyme kinetics studies requiring precise thermal hold conditions over multi-hour durations
• Material testing such as polymer melt index conditioning or asphalt softening point determination (ASTM D36)

FAQ

Does the BWS series support continuous unattended operation?
Yes—when filled to the minimum operating level and configured with dry-run protection enabled, the unit maintains stable temperature for up to 72 hours. However, manual reset after any dry-run event is mandatory before resuming heating.
Can the circulation pump be disabled for pure water bath use?
Yes—pump operation is independently controlled via front-panel toggle; disabling circulation converts the unit to a high-uniformity static water bath.
Is the temperature sensor calibrated traceable to national standards?
Each unit ships with a factory calibration certificate referencing internal Pt100 sensor characterization; end-user recalibration using a NIST-traceable reference thermometer is recommended annually.
What maintenance is required to ensure long-term accuracy?
Monthly inspection of water level sensor contacts, quarterly descaling of the inner tank with 5% citric acid solution, and annual verification of heater resistance and insulation integrity.
Are replacement parts such as lids or racks available separately?
Yes—Yiheng supplies OEM stainless steel lids, ABS beaker inserts, and pump modules under part numbers aligned with each BWS model variant.