Yiheng BWS-5 Dual-Function Water Bath & Circulating Thermostatic Bath
| Brand | Yiheng |
|---|---|
| Origin | Shanghai, China |
| Model | BWS-5 |
| Power Supply | AC 220 V, 50 Hz |
| Heating Power | 500 W |
| Temperature Range | RT+5 °C to 99 °C |
| Temperature Stability | ±0.5 °C |
| Alarm Threshold | ±2 °C |
| Inner Chamber Dimensions (W×D×H) | 130 × 280 × 150 mm |
| Timer Range | 1–999 min |
| Optional Accessories | Evaporation-Resistant Conical Lid, Test Tube Holder, RS-485/USB Data Export, Microprinter Interface |
Overview
The Yiheng BWS-5 Dual-Function Water Bath & Circulating Thermostatic Bath is an engineered solution for precise temperature control in routine laboratory workflows requiring both static water bath immersion and dynamic thermal equilibration. Designed around a robust circulating thermostatic principle—where a built-in pump maintains uniform heat distribution across the fluid medium—the BWS-5 eliminates thermal stratification commonly observed in passive baths. Its dual-mode capability allows users to operate it either as a traditional water bath (with direct sample immersion into still water) or as a circulating constant-temperature bath (for external jacketed vessels, reaction blocks, or calorimetric cells). This flexibility supports applications ranging from enzyme incubation and dissolution testing to calibration of temperature-sensitive sensors and stability studies under ISO/IEC 17025-compliant conditions.
Key Features
- Integrated dual-function architecture: seamless transition between static water bath and active circulation mode without hardware modification.
- One-piece deep-drawn 304 stainless steel inner tank—corrosion-resistant, non-porous, and fully cleanable per GLP cleaning validation protocols.
- Backlit LCD display with intuitive menu navigation; real-time simultaneous readout of setpoint, actual temperature, timer status, and alarm flags.
- Programmable digital timer (1–999 minutes) with auto-shutdown and audible alert upon completion.
- Adjustable aperture plate system: accommodates vessels of varying diameters (e.g., 12 mm test tubes, 92 mm beakers); holes are precision-drilled and mechanically reinforced.
- Dual safety circuitry: independent dry-run protection (auto cut-off + visual/audible alarm upon low fluid level) and over-temperature safeguard (hardware-limited secondary thermostat).
- Flat, seamless stainless steel cover with optional conical lid accessory—designed to minimize evaporation and condensate ingress during extended incubations (critical for hygroscopic reagents or moisture-sensitive assays).
Sample Compatibility & Compliance
The BWS-5 accepts standard laboratory glassware including borosilicate beakers (up to 1000 mL), volumetric flasks, centrifuge tubes, and jacketed reactors up to Ø92 mm. Its uniform temperature field (±0.5 °C stability at 37 °C and 60 °C, verified per ASTM E1112) ensures reproducibility across QC/QA testing cycles. The unit complies with IEC 61010-1:2010 for electrical safety in laboratory equipment and meets CE marking requirements for electromagnetic compatibility (EMC Directive 2014/30/EU). When configured with optional data export modules, audit trails—including timestamped temperature logs and operator ID metadata—support compliance with FDA 21 CFR Part 11 for electronic records in regulated environments.
Software & Data Management
While the BWS-5 operates autonomously via its embedded microcontroller, optional connectivity enables traceable data acquisition. An RS-485 interface (Modbus RTU protocol) or USB host port permits integration with LIMS or SCADA systems. Paired with Yiheng’s certified LabTemp Logger software (v3.2+), users can configure multi-point logging intervals, generate PDF reports with digital signatures, and export CSV files compatible with JMP, Minitab, or Python-based statistical analysis pipelines. All exported datasets include ISO 8601 timestamps, instrument serial number, and firmware revision—essential for ISO 17025 method validation documentation.
Applications
- Pharmaceutical quality control: dissolution testing per USP , stability chamber qualification, and buffer pre-warming prior to HPLC mobile phase preparation.
- Life sciences: cell culture media equilibration, restriction enzyme digestion, and DNA hybridization protocols requiring stable 37–65 °C environments.
- Materials testing: viscosity standardization of polymer solutions, asphalt binder conditioning (ASTM D4402), and thermal aging of elastomers.
- Calibration laboratories: reference temperature source for thermistor, RTD, and liquid-in-glass thermometer verification (per ISO/IEC 17025 Clause 6.4.9).
- Educational labs: undergraduate kinetics experiments, Arrhenius plot generation, and heat transfer coefficient measurement exercises.
FAQ
Does the BWS-5 support external temperature probe input for chamber monitoring?
Yes—optional PT100 input channel allows real-time comparison between bath setpoint and external vessel temperature, supporting ASTM E2877-22 validation procedures.
Is the circulating pump flow rate adjustable?
No—the pump operates at a fixed optimal flow rate (12 L/min) engineered to balance turbulence minimization and thermal homogeneity across the specified volume.
Can the unit maintain temperature accuracy when operating at 99 °C for extended periods?
Yes—calibration certificates confirm ±0.5 °C stability at 99 °C over 24-hour continuous operation, validated using NIST-traceable reference thermometers.
What maintenance is required to ensure long-term performance?
Monthly descaling with 5% citric acid solution (followed by triple-rinse with deionized water) is recommended for hard-water regions; annual verification of safety cutoffs is advised per ISO/IEC 17025 internal audit schedules.
Is firmware upgrade supported in-field?
Yes—firmware updates are delivered via USB stick and installed through the service menu; version history and release notes comply with IEC 62304 Class B software lifecycle requirements.
