Zuofei ZWH-10 Precision Water Bath Circulator

Overview

The Zuofei ZWH-10 Precision Water Bath Circulator is a microprocessor-controlled, laboratory-grade constant-temperature immersion system engineered for thermal stability, repeatability, and operational safety in routine and research-grade applications. It operates on the principle of convective heat transfer via a fully immersed, cast-in-place heating plate coupled with forced convection through an integrated low-noise circulation pump (optional configuration). The unit maintains precise setpoint control across its full operating range (ambient +5°C to 100°C) using a digital PID algorithm with adaptive tuning, minimizing overshoot and ensuring long-term thermal uniformity within the bath chamber. Designed for integration into QC workflows, enzymatic assays, sample conditioning, and calibration procedures, the ZWH-10 complies with general requirements for temperature-controlled equipment outlined in ISO/IEC 17025:2017 (clause 6.4.3) and supports GLP-compliant documentation when paired with external data logging systems.

Key Features

• One-piece, deep-drawn 304 stainless steel bath tank with PTFE-coated interior surface—resistant to corrosion from aqueous buffers, saline solutions, and mild organic solvents.
• Robust cold-rolled steel outer housing with matte epoxy powder coating—provides mechanical durability and resistance to environmental oxidation in shared lab environments.
• High-resolution 4.3-inch TFT color display with intuitive touch-sensitive interface—enables real-time monitoring of setpoint, actual temperature, elapsed time, and system status without menu nesting.
• Dual independent safety mechanisms: bimetallic overtemperature cut-off switch (resettable at 110°C) and optical liquid-level sensor—prevents dry-run operation and thermal runaway under low-fluid or accidental drain conditions.
• Cast aluminum heating plate bonded directly to the bath floor—ensures optimal thermal contact, minimizes thermal gradients (<±0.5°C across 10 L volume at 37°C), and eliminates hot-spot formation common in coil-type heaters.
• Low-power consumption design (100 W nominal)—optimized for continuous unattended operation in energy-conscious laboratories; meets IEC 61000-3-2 harmonic current emission standards.

Sample Compatibility & Compliance

The ZWH-10 accommodates standard laboratory glassware including beakers (up to 1 L), test tubes (10–25 mm OD), flasks, and cuvette racks. Its open-bath configuration allows direct immersion of probes, sensors, and reaction vessels without lid interference. The unit is CE-marked per Directive 2014/30/EU (EMC) and 2014/35/EU (LVD). While not certified to UL/CSA standards out-of-the-box, it conforms to essential safety and performance criteria referenced in ASTM E145–22 (Standard Specification for Gravity-Convection and Forced-Ventilation Ovens) and USP (Thermal Analysis Apparatus) for water-based thermal conditioning. For regulated environments (e.g., pharmaceutical QA labs), users may implement audit-trail-capable external recording via RS485 Modbus RTU output (available upon request).

Software & Data Management

The ZWH-10 features embedded firmware supporting local parameter storage (up to 10 user-defined profiles), event logging (power-on, setpoint change, alarm triggers), and real-time temperature history (last 72 hours at 10-second intervals). Data export is enabled via USB-C port (FAT32 formatted drive required) in CSV format—compatible with Excel, LabArchives, and ELN platforms. Optional PC software (Zuofei TempLink v2.1) provides remote monitoring, trend visualization, and configurable alarm notifications via email/SNMP traps. All logged data includes timestamp, bath temperature, setpoint deviation, and system health flags—supporting traceability under FDA 21 CFR Part 11 when deployed with validated electronic signature modules.

Applications

• Enzyme kinetics studies requiring stable incubation at 25°C, 37°C, or 60°C.
• Viscosity standardization of calibration oils prior to rotational rheometry (ASTM D445).
• Cell culture reagent equilibration and pre-warming of media components.
• Accelerated stability testing of pharmaceutical formulations per ICH Q1A(R3).
• Calibration of liquid-in-glass thermometers and RTDs against NIST-traceable references.
• Sample thawing and homogenization of lipid emulsions in food science laboratories.

FAQ

Is the ZWH-10 suitable for use with corrosive solutions such as sodium hydroxide or hydrochloric acid?

No. While the PTFE-coated stainless steel bath resists mild corrosion, concentrated acidic or alkaline solutions will degrade the coating over time. Use only deionized water, phosphate-buffered saline, or ethanol/water mixtures below 30% v/v.
Does the unit include a circulation pump by default?

The base model ZWH-10 operates in static bath mode. An optional 4 L/min magnetic-drive circulation pump (model ZWH-CIRC-10) is available for applications requiring active fluid exchange or external jacketed reactor coupling.
Can temperature data be exported in real time to a LIMS?

Yes—via RS485 Modbus RTU interface (add-on module). Integration requires third-party LIMS-side Modbus master configuration and mapping of register addresses 40001–40005 (current temp, setpoint, status, error code, uptime).
What is the recommended maintenance schedule?

Drain and rinse the bath weekly if used daily; descale every 3 months using 5% citric acid solution at 60°C for 2 hours. Inspect the optical level sensor window monthly for biofilm accumulation.
Is validation documentation (IQ/OQ) available?

Factory-issued IQ/OQ templates compliant with ISO 13485 and GAMP5 are provided free of charge. Full protocol execution and certification require on-site support billed separately.