Julabo PURA 4 Universal Water Bath

Overview

The Julabo PURA 4 Universal Water Bath is a precision-engineered, compact temperature-controlled bath designed for reliable and repeatable thermal conditioning of samples in research, quality control, and routine laboratory environments. Built upon Julabo’s decades-long heritage in thermal management instrumentation, the PURA 4 employs advanced PID-based temperature regulation with digital feedback control to maintain exceptional thermal stability across its operational range of +18 °C to +99.9 °C. Unlike conventional water baths relying on basic thermostatic switches, the PURA 4 integrates a high-resolution Pt100 sensor, optimized heater geometry, and intelligent thermal load compensation—ensuring consistent performance even during prolonged operation or partial bath filling. Its robust stainless-steel bath chamber, sealed electronics housing, and IP21-rated front panel provide protection against incidental splashes and dust ingress, meeting fundamental safety requirements for general-purpose lab use under ISO/IEC 17025-aligned workflows.

Key Features

• High-stability temperature control: ±0.15 °C stability (with optional bath cover installed), verified per DIN 12879 Annex A protocols
• Full-immersion removable platform for uniform heat transfer and secure sample positioning
• LED display with 0.1 °C resolution and intuitive push-button interface; all controls are waterproof-rated (IP21)
• Integrated dry-run protection: automatic heater shutdown if liquid level falls below minimum threshold
• Optimized bath geometry with angled rim design to redirect condensate from transparent covers back into the bath—minimizing evaporation loss and maintaining setpoint integrity
• Compact footprint (21 × 35 × 22 cm) suitable for benchtop integration in space-constrained labs, including biosafety cabinets and analytical hoods
• 2 kW heating capacity enables rapid ramp-up to 99.9 °C, while low thermal inertia ensures responsive recovery after sample insertion

Sample Compatibility & Compliance

The PURA 4 accommodates standard glassware—including test tubes (up to 25 mm diameter), cuvettes, beakers, and small flasks—via optional accessories such as stainless-steel multi-hole covers, adjustable tube racks, and cooling rings. Its bath volume range (0.8–4.5 L) supports both micro-scale assays and larger-volume incubations without compromising thermal homogeneity. The unit complies with IEC 61010-1:2010 for electrical safety in laboratory equipment and meets EN 60529 for ingress protection (IP21). While not certified for GMP or GLP environments out-of-the-box, its stable thermal output, traceable calibration support (via external Pt100 probe input), and audit-ready documentation make it suitable for use in regulated settings when integrated into validated SOPs—particularly for non-critical pre-analytical steps such as enzyme reactivation, DNA denaturation, or buffer equilibration.

Software & Data Management

The PURA 4 operates as a standalone instrument with no embedded data logging or PC connectivity. However, its analog output (0–10 V) allows integration with third-party data acquisition systems for time-stamped temperature monitoring. For laboratories requiring electronic records compliant with FDA 21 CFR Part 11, users may pair the bath with external validated loggers (e.g., calibrated thermistor arrays or wireless PT100 transmitters) and document calibration history, maintenance logs, and usage parameters manually within their LIMS or ELN. Julabo provides comprehensive calibration certificates upon request, traceable to national standards (DKD/DAkkS-accredited labs).

Applications

• Routine sample warming and thawing in clinical and diagnostic labs (e.g., serum, plasma, tissue homogenates)
• Temperature-dependent reaction initiation in biochemistry (e.g., restriction digests, ligase incubations)
• Pre-conditioning of polymers and composites prior to tensile or rheological testing
• Accelerated corrosion testing using standardized saline or acidic solutions
• Dental material curing validation per ISO 4049 guidelines
• Food microbiology media preparation and holding at defined temperatures (e.g., ISO 6887, AOAC 977.27)
• Pharmaceutical dissolution medium conditioning in early-stage formulation studies

FAQ

What is the minimum and maximum recommended fill volume for optimal temperature stability?
The bath achieves rated stability (±0.15 °C) between 0.8 L and 4.5 L. Below 0.8 L, thermal mass is insufficient for consistent control; above 4.5 L, overflow risk increases and heater duty cycle rises significantly.
Can the PURA 4 be used for boiling applications?
Yes—it maintains stable operation up to +99.9 °C at sea level. For sustained boiling, use the optional transparent acrylic cover to reduce evaporation and improve energy efficiency.
Is the unit compatible with external chillers for sub-ambient operation?
No. The PURA 4 is a heating-only bath. Sub-ambient control requires a circulating chiller/heater system (e.g., Julabo F25 or PRESTO series).
Does the PURA 4 include a drain valve?
No—the PURA 4 model does not feature a built-in drain valve. Drainage requires manual siphoning or tilting. Larger PURA models (PURA 10 and above) include factory-installed drainage ports.
How often should calibration verification be performed?
We recommend quarterly verification using an independent, NIST-traceable reference thermometer—especially before critical experiments or after extended continuous operation (>72 hours).