Yiheng HWS Series Constant Temperature Water Bath

Overview

The Yiheng HWS Series Constant Temperature Water Bath is a precision thermal management instrument engineered for stable, uniform heating of samples in laboratory environments. Operating on resistive heating principles with direct immersion-based thermal transfer, the unit maintains setpoint temperature through proportional-integral (PI) control logic executed by a high-accuracy microprocessor controller. Designed for applications requiring consistent thermal conditions—such as enzyme incubation, sample thawing, reagent warming, dissolution testing, and low-temperature chemical reactions—the HWS series delivers reliable performance across four standard capacity variants (4.9 L to 19.8 L). Its non-circulating design ensures quiet, maintenance-free operation suitable for benchtop use in teaching laboratories, QC labs, and R&D facilities where precise, localized heating—not forced convection—is the primary requirement.

Key Features

• Electropolished stainless steel inner tank resistant to corrosion and thermal fatigue, facilitating long-term durability and easy cleaning.
• Adjustable well inserts enabling flexible configuration for vessels of varying diameters; compatible with standard glassware including beakers, flasks, and test tubes.
• Digital microcomputer temperature controller with real-time display, offering ±0.5 °C temperature stability at setpoint and programmable timer function (1–999 minutes).
• Independent over-temperature protection circuit with audible and visual alarm activation when deviation exceeds ±2 °C—ensuring sample integrity and operator safety.
• Four standardized configurations: 2-hole (HWS-12), dual-row 4-hole (HWS-24), dual-row 6-hole (HWS-26), and dual-row 8-hole (HWS-28), each optimized for spatial efficiency and thermal uniformity.
• Front-panel accessible controls with intuitive interface; no external software required for basic operation.

Sample Compatibility & Compliance

The HWS series accommodates a broad range of sample containers—from 10 mL test tubes to 1 L Erlenmeyer flasks—without requiring custom fixtures. Its open-bath architecture supports passive heat exchange, making it suitable for protocols sensitive to mechanical agitation or shear stress. While not certified for GMP or GLP environments out-of-the-box, the unit complies with general electrical safety standards applicable to Class I laboratory equipment (IEC 61010-1). Optional RS485 serial interface enables integration into centralized lab monitoring systems for audit-ready temperature logging, supporting traceability requirements under ISO/IEC 17025 and FDA 21 CFR Part 11 when paired with compliant data acquisition software.

Software & Data Management

Base configuration operates independently via front-panel controls. For enhanced data governance, optional accessories include: (1) an intelligent programmable LCD temperature controller with ramp-soak profiles and password-protected parameter locking; and (2) RS485 communication module with accompanying Windows-compatible PC software for remote monitoring, real-time graphing, and CSV export of time-stamped temperature logs. When deployed with validated software and defined SOPs, this configuration supports electronic record retention aligned with ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available).

Applications

• Controlled warming of biological reagents (e.g., fetal bovine serum, restriction enzymes) prior to use in molecular biology workflows.
• Standardized conditioning of polymer solutions and adhesives during viscosity pre-equilibration steps.
• Accelerated stability testing of pharmaceutical formulations under accelerated aging conditions (per ICH Q1A guidelines).
• Calibration support for thermometers and temperature probes using fixed-point reference baths.
• Pre-heating of solvents prior to chromatographic injection or extraction procedures.
• Use as auxiliary heating source in conjunction with analytical instruments requiring stabilized bath temperatures (e.g., viscometers, density meters).

FAQ

Is the HWS series suitable for oil bath operation?
Yes—stainless steel construction and temperature range up to 99 °C permit safe use with silicone oils and mineral oils; however, users must verify oil flash point and thermal stability limits prior to deployment.
Does the unit include calibration documentation?
Factory calibration certificate is provided upon request; users are responsible for periodic verification per internal quality protocols or ISO/IEC 17025 requirements.
Can the timer function be disabled for continuous operation?
Yes—the timer can be set to “0” or bypassed entirely, allowing uninterrupted heating until manually powered down.
What is the typical warm-up time to reach 37 °C from ambient?
Approximately 12–18 minutes for the HWS-24 model (9.9 L), depending on ambient temperature and load volume.
Are replacement well inserts available separately?
Yes—custom-machined stainless steel inserts for non-standard vessel geometries can be ordered directly from Yiheng’s authorized distribution network.