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

Overview

The Shanghai Yiheng BWS Series Dual-Function Water Bath & Circulating Constant-Temperature Bath is engineered for precise thermal control in laboratory environments where versatility, safety, and reproducibility are critical. Designed using Couette-flow-based convection principles and optimized internal circulation architecture, the BWS series operates as both a standard immersion water bath and a temperature-stabilized circulating bath—eliminating the need for separate instruments in routine QC, calibration, sample incubation, and reaction temperature maintenance tasks. Unlike conventional single-purpose units, its dual-mode configuration supports simultaneous multi-vessel processing (e.g., beakers, flasks, test tubes) while maintaining uniform thermal distribution across the working chamber. The system employs PID-controlled resistive heating with digital feedback loop regulation, delivering stable setpoint adherence within ±0.3°C under steady-state conditions—a specification validated per ISO/IEC 17025-compliant thermal mapping protocols.

Key Features

• Dual-function design: seamless transition between open-bath water bath mode and closed-loop circulating bath mode without hardware modification
• One-piece deep-drawn stainless steel inner tank (AISI 304), corrosion-resistant and fully cleanable; eliminates seam traps for microbial or residue accumulation
• Integrated dry-run protection: automatic heater shutdown upon liquid level detection below operational threshold—prevents thermal damage and extends component service life
• Independent mechanical over-temperature safety cutoff (non-software dependent), compliant with IEC 61010-1 Class II requirements for laboratory equipment
• Backlit LCD interface with real-time display of setpoint, actual temperature, timer status, and alarm flags; menu-driven navigation with intuitive iconography
• Adjustable aperture plate system supporting five standardized bore diameters (Φ32, Φ52, Φ72, Φ92, Φ112 mm) for flexible vessel accommodation
• Flat-top stainless steel cover and optional peaked lid design minimizes condensation ingress and evaporation loss during extended operation
• Removable stainless steel support grid shields heating elements and PT100 sensor from mechanical impact during loading/unloading

Sample Compatibility & Compliance

The BWS series accommodates a broad range of sample containers—including borosilicate glass beakers (50–1000 mL), reaction flasks, centrifuge tubes, and cuvettes—across all model variants. Its chamber geometry and aperture layout conform to ASTM E2738-21 guidelines for thermal uniformity assessment in liquid-phase temperature control devices. Units meet CE marking requirements for electromagnetic compatibility (EN 61326-1) and low-voltage safety (EN 61010-1). Optional configurations support GLP/GMP-aligned workflows through RS-485 Modbus RTU or USB host interface integration, enabling audit-trail-capable data logging when paired with validated third-party software platforms.

Software & Data Management

While the base unit operates via embedded firmware without external software dependency, optional connectivity modules enable traceable temperature monitoring and documentation. The RS-485 port supports bidirectional communication with SCADA systems or LabVantage/LIMS platforms using standard Modbus register mapping. A USB host interface permits direct connection to UVC-compliant USB flash drives for timestamped CSV export of temperature/time logs (sample interval configurable from 1 s to 60 min). Optional thermal printer integration (via TTL-level serial output) provides hard-copy records suitable for FDA 21 CFR Part 11 Annex 11–aligned environments when used with calibrated time sources and signed print templates.

Applications

The BWS series serves critical roles across regulated and research-intensive domains: enzyme activity assays requiring strict thermal consistency (e.g., USP analytical instrument qualification); pharmaceutical dissolution testing per USP ; calibration of thermometers and RTDs against NIST-traceable references; cell culture pre-warming in biomedical labs; polymer viscosity conditioning prior to rheological analysis; and stability testing of excipients under accelerated aging protocols (ICH Q1A). Its RT+5°C to 99°C operating envelope covers >95% of aqueous-based thermal protocols defined in ISO 17025-accredited laboratories.

FAQ

Does the BWS series support external temperature probe input for chamber validation?
No—the system relies exclusively on its factory-calibrated internal PT100 sensor. For IQ/OQ validation, users must employ external calibrated reference thermometers per ISO/IEC 17025 clause 6.5.
Can the circulation pump be disabled for pure water bath operation?
Yes—circulation is automatically suspended in open-bath mode; flow resumes only when the cover is sealed and circulation mode is manually selected.
Is the stainless steel tank electropolished or passivated?
Standard units feature mechanically polished AISI 304 surfaces; electropolishing and nitric acid passivation are available as custom options (lead time +10 business days).
What is the maximum permissible load volume for BWS-20 in circulating mode?
Maximum recommended fluid volume is 20 L; exceeding this may impair thermal homogeneity and trigger low-flow alarms.
Are calibration certificates provided with shipment?
Factory calibration reports (including as-found/as-left data at 37°C, 60°C, and 90°C) are included; UKAS-accredited certificates require separate purchase and additional lead time.