MEMMERT WNB45 Water Bath

Overview

The MEMMERT WNB45 is a precision-engineered laboratory water bath designed for stable, uniform thermal conditioning of samples across life science, pharmaceutical, chemical, and materials research applications. Operating on the principle of convective heat transfer within a thermostatically controlled aqueous medium, the WNB45 delivers high reproducibility in temperature maintenance—critical for enzymatic assays, cell culture preparation, solvent evaporation, reaction kinetics studies, distillation support, and incubation of temperature-sensitive reagents. Its 45-liter stainless steel bath provides scalable capacity while maintaining tight thermal homogeneity (< ±0.2 °C at 37 °C, typical), validated per DIN 12879. The unit supports both static and dynamic thermal protocols—including timed ramp-and-hold, delayed start, and continuous boil mode—enabling integration into standardized workflows compliant with ISO/IEC 17025 and FDA 21 CFR Part 11 when paired with MEMMERT’s optional data logging software.

Key Features

• PID-controlled temperature regulation with quad-wire Pt100 sensor (two independent sensors in E-type configuration) ensures long-term stability and traceable accuracy to ±0.1 °C setpoint resolution.
• Triple-stage overtemperature protection (E-type) comprises: (1) electronic safety cutoff at +10 °C above setpoint; (2) user-configurable electronic limit (TWW/TWB); and (3) fail-safe mechanical thermostat (TB) activated at +30 °C above bath-rated maximum—meeting IEC 61010-1 Class II requirements.
• Programmable timer with extended range (up to 999 hours in E-type) supports unattended operation for overnight or multi-day experiments, with configurable modes: immediate start, delayed activation, hold duration, and time-dependent temperature profiles.
• Corrosion-resistant 316 stainless steel inner bath and housing ensure durability under repeated cleaning, sterilization cycles, and exposure to saline or buffered solutions.
• LED display with alarm indication provides real-time feedback on operational status, error codes, and active safety interventions—fully documented in MEMMERT’s service manual for audit readiness.
• Modular accessory ecosystem includes gabled or flat lids, orbital shaker modules (WB/WBU variants only), adjustable-height support frames, conical flask holders (100–500 mL), and standardized tube racks (14.5–32 mm diameter), all engineered for secure placement and minimal thermal shadowing.

Sample Compatibility & Compliance

The WNB45 accommodates standard laboratory glassware including Erlenmeyer flasks (up to 500 mL), volumetric cylinders, centrifuge tubes, and microcentrifuge racks. Its internal geometry (590 × 350 × 220 mm) permits simultaneous immersion of multiple vessels without compromising circulation efficiency. All wetted surfaces comply with USP and EU Pharmacopoeia Chapter 3.1 for extractables testing. The system meets CE marking requirements under the Low Voltage Directive (2014/35/EU) and EMC Directive (2014/30/EU), and conforms to DIN EN 61326-1 for laboratory equipment electromagnetic compatibility. Firmware architecture supports GLP-compliant operation: event logs (including temperature deviations, timer triggers, and safety interventions) are timestamped and non-erasable; optional RS485/USB interface enables connection to LIMS or ELN platforms with full 21 CFR Part 11 audit trail capability.

Software & Data Management

While the WNB45 operates autonomously via its front-panel interface, MEMMERT’s optional COMET software (v5.2+) enables remote monitoring, parameter export, and compliance reporting. Through USB or RS485 connectivity, users can record time-stamped temperature traces at user-defined intervals (1–60 s), generate PDF calibration reports aligned with ISO/IEC 17025 Annex A.2, and archive raw data in CSV format for statistical process control (SPC) analysis. All logged events—including overtemperature alarms, sensor faults, and power interruptions—are stored with cryptographic integrity verification. Firmware updates are digitally signed and delivered via MEMMERT’s secure customer portal, ensuring traceability per GxP change control procedures.

Applications

• Pharmaceutical QC: Dissolution testing support (USP ), buffer equilibration prior to HPLC injection, and thermal validation of excipient stability.
• Life Sciences: DNA hybridization pre-incubation, antibody dilution warming, gel electrophoresis buffer conditioning, and microbial culture media tempering.
• Chemistry Labs: Controlled reflux setups, solvent removal under reduced pressure, kinetic studies requiring precise thermal ramping, and polymer solubilization protocols.
• Materials Testing: Thermal aging of composites, viscosity standardization of calibration oils, and moisture content determination via gravimetric drying support.
• Academic Research: Reproducible thermal challenge assays in toxicology, enzyme thermolability profiling, and teaching lab demonstrations of Arrhenius kinetics.

FAQ

What is the difference between the B-type and E-type controllers?
The B-type offers basic PID control with dual overtemperature protection and a 99-hour timer; the E-type adds a second Pt100 sensor, triple-stage safety cutoff, 999-hour timing, and programmable temperature-vs.-time profiles.
Can the WNB45 be used for oil baths?
No—the WNB45 is specifically designed for aqueous media. For oil-based applications, MEMMERT offers the OB45 oil bath variant with modified heating elements and thermal insulation.
Is the shaker module compatible with all lid configurations?
Orbital shaking is only available with the gabled lid (order code L1 or L4) and requires the dedicated tray support kit (L5); it is not supported on flat-lid configurations or oil bath versions.
How is temperature uniformity validated in this model?
MEMMERT performs factory validation using nine-point mapping per DIN 12879, with results provided in the Certificate of Conformance; users may repeat verification using calibrated reference probes at defined grid positions.
Does the unit support external temperature probe input for sample-specific monitoring?
No—the WNB45 regulates bath temperature only; however, third-party PT100 probes can be immersed alongside samples and logged externally via COMET software using auxiliary analog inputs.