HKM WB-502S Super Precision Circulating Water Bath

Overview

The HKM WB-502S Super Precision Circulating Water Bath is an engineered laboratory thermal platform designed for stable, uniform, and reproducible temperature control in applications requiring high-fidelity thermal environments. Utilizing a closed-loop liquid circulation system with a built-in 8 L/min pump, this unit maintains precise thermal equilibrium across the entire bath chamber via forced convection—eliminating stratification and enhancing heat transfer efficiency compared to static water baths. Its operating range spans from ambient +5 °C to 99 °C, with a certified temperature uniformity of ±0.1 °C at setpoint—achievable through microprocessor-driven PID control featuring auto-tuning capability. The device complies with fundamental safety and electromagnetic compatibility requirements per IEC 61010-1 for laboratory electrical equipment, and its construction adheres to corrosion-resistant material standards appropriate for long-term aqueous operation in regulated lab settings.

Key Features

• One-piece seamless 304 stainless steel inner tank—prevents leakage, resists chemical degradation, and facilitates rapid cleaning and validation.
• Waveform immersion heating element—distributes thermal energy uniformly across the bath volume, minimizing localized hot spots and improving spatial temperature consistency.
• Microprocessor-controlled PID algorithm with self-tuning functionality—reduces overshoot, accelerates stabilization time (<15 min to ±0.1 °C at 37 °C), and sustains setpoint accuracy over extended durations.
• Programmable digital timer with automatic power cutoff—supports unattended operation up to 99 hours 59 minutes; configurable alarm triggers upon completion or deviation.
• Adjustable upper-limit tracking alarm—user-definable threshold prevents thermal excursion beyond process-critical boundaries, supporting risk mitigation in GLP-compliant workflows.
• Ergonomically angled LED display panel—improves visibility and reduces parallax error during operation; integrated front-panel controls simplify parameter entry and status monitoring.
• Dedicated external circulation port—enables connection to auxiliary systems (e.g., reaction jackets, viscometer temperature control units, or external sample holders) without compromising internal bath stability.
• Independent bottom-mounted drain valve—permits complete fluid evacuation without tilting or disassembly, supporting routine maintenance, calibration verification, and cross-contamination prevention.

Sample Compatibility & Compliance

The WB-502S accommodates standard laboratory glassware including beakers (up to 1000 mL), test tubes, cuvettes, and enzymatic assay vessels placed directly into the bath chamber or mounted on optional rack inserts. Its 320 × 300 × 110 mm working volume supports multi-vessel simultaneous incubation under identical thermal conditions. The unit meets general-purpose laboratory safety classifications under IEC 61010-1 (Edition 3.1) and incorporates double-insulated heating circuits with ground-fault detection. While not certified to ISO/IEC 17025 or FDA 21 CFR Part 11 out-of-the-box, its deterministic control architecture, audit-ready timer logs, and hardware-based thermal fail-safes provide foundational traceability for internal quality procedures aligned with ISO 13485 (medical device labs) and ISO 9001 (R&D/QC environments).

Software & Data Management

This model operates as a standalone analog-digital hybrid instrument with no embedded data logging or PC interface. All operational parameters—including set temperature, elapsed time, current bath temperature, and alarm status—are displayed in real time on the front-panel LED interface. For laboratories requiring electronic record retention, third-party USB or RS-232 data loggers (e.g., Omega OM-DAQPRO-5300 series) may be connected via optional analog output modules (0–5 V or 4–20 mA signal conversion kits). Configuration changes are non-volatile and retained after power cycling. Firmware updates are not supported; however, calibration offsets can be manually adjusted using factory-provided service routines accessible via diagnostic mode.

Applications

• Enzyme kinetics assays requiring strict thermal control between 25–45 °C for reproducible Michaelis-Menten parameter derivation.
• Cell culture media pre-warming prior to sterile handling, ensuring minimal thermal shock to sensitive mammalian lines.
• Standardization of viscosity measurements per ASTM D445 and ISO 3104, where bath temperature must remain within ±0.05 °C of reference value during capillary flow timing.
• Accelerated stability testing of pharmaceutical formulations per ICH Q1A(R2), utilizing controlled thermal stress profiles across multiple setpoints.
• Calibration of liquid-in-glass thermometers and RTD probes against NIST-traceable references in metrology labs.
• Supporting electrophoresis buffer temperature regulation to prevent gel distortion during prolonged runs.

FAQ

Does the WB-502S support external temperature probe input for chamber feedback control?
No—the unit relies exclusively on its internal PT100 sensor located near the heater base; external probe integration is not supported.
Is deionized water mandatory for operation?
Deionized or distilled water is strongly recommended to prevent scale buildup on the heating element and inner tank surface, especially above 60 °C.
Can the circulation pump be disabled for static bath operation?
Yes—the pump is independently switchable via rear-panel toggle, allowing use as a conventional non-circulating water bath when required.
What is the maximum allowable fill level relative to the tank height?
Fill level must not exceed 20 mm below the top rim to ensure proper air circulation around the lid seal and avoid overflow during thermal expansion.
Are calibration certificates provided with shipment?
Factory calibration documentation (as-found/as-left data at three points: 37 °C, 60 °C, and 85 °C) is available upon request at time of order; NIST-traceable certification incurs additional lead time and cost.