Julabo PURA22 General-Purpose Circulating Water Bath

Overview

The Julabo PURA22 General-Purpose Circulating Water Bath is an engineered solution for precise, stable, and reliable temperature control in routine laboratory applications. Designed and manufactured in Germany, it operates on the principle of forced convection via an integrated circulation pump—ensuring uniform thermal distribution throughout the bath medium without external recirculation units. Its operational range spans from +18.0 °C to +99.9 °C, making it suitable for incubation, enzymatic assays, sample equilibration, dissolution testing, and material conditioning where sub-degree thermal stability is critical. The unit employs a high-grade stainless steel inner bath, corrosion-resistant heating coil, and sealed electronic architecture compliant with IEC 61000-6-3 (EMC) and IEC 61010-1 (safety). All models meet DIN 12876-1 Class I (NFL) requirements for laboratory equipment used with non-hazardous liquids, supporting GLP-compliant workflows when paired with audit-trail-capable software (e.g., Julabo’s EASYTEMP via optional RS232 interface).

Key Features

• High-resolution 0.1 °C digital display with LED backlighting for clear visibility under ambient lab lighting conditions
• IP43-rated waterproof control panel and tactile membrane switches, minimizing ingress risk from splashes or condensation
• Integrated condensate return edge design—redirects evaporative condensate back into the bath during prolonged high-temperature operation, reducing manual refilling frequency
• Full-immersion removable platform standard, enabling flexible placement of flasks, beakers, or test tubes while maintaining consistent heat transfer
• Automatic dry-run protection circuitry prevents heater activation when fluid level falls below safe operating threshold
• Standard drain valve located at the bath base for rapid, spill-free medium exchange—critical for cross-contamination prevention between experiments
• Stainless steel construction (inner bath and heating elements) ensures long-term resistance to oxidation, chemical degradation, and microbial adhesion
• Thermal stability of ±0.15 °C (measured at center point, load-independent per DIN 12876-1 test protocol) verified across full volume range (0.8–36 L)

Sample Compatibility & Compliance

The PURA22 accommodates a wide range of sample containers—including glassware up to 1 L capacity, multi-well plates, and immersion probes—within its 55 × 27 cm open bath area (depth: 18 cm). Its non-reactive stainless steel interior and absence of silicone-based gaskets or plastic components ensure compatibility with aqueous buffers, saline solutions, ethanol-water mixtures, and mild organic solvents (e.g., isopropanol ≤30% v/v). The device conforms to DIN 12876-1 Class I (NFL), indicating suitability for use with non-flammable, non-toxic, and non-corrosive media. It supports ISO/IEC 17025 traceability when calibrated using NIST-traceable reference thermometers (e.g., PRTs or certified thermocouples). For regulated environments, optional RS232 connectivity enables integration with LIMS or electronic lab notebooks (ELN) supporting 21 CFR Part 11 compliance when used with validated firmware and access-controlled software.

Software & Data Management

While the PURA22 operates as a standalone instrument with intuitive front-panel controls, optional RS232 serial interface allows bidirectional communication with Julabo’s EASYTEMP PC software. This platform provides real-time temperature logging, remote setpoint adjustment, alarm event timestamping, and export of CSV-formatted datasets compatible with statistical analysis tools (e.g., JMP, Minitab, Python pandas). Audit trail functionality records user ID, parameter changes, and system status transitions—fulfilling ALCOA+ data integrity principles required under GxP frameworks. No proprietary drivers are required; standard Windows COM port configuration suffices. Firmware updates are performed via USB-to-serial adapter (not included), ensuring continued alignment with evolving cybersecurity and regulatory expectations.

Applications

• Routine sample incubation and pre-warming prior to spectroscopic, chromatographic, or electrophoretic analysis
• Controlled dissolution testing per USP and Ph. Eur. 2.9.3 protocols, particularly for solid oral dosage forms
• Biological activity assays requiring strict thermal consistency (e.g., enzyme kinetics, ligand-binding studies)
• Accelerated aging tests in materials science (polymer softening, coating adhesion, thermal expansion coefficient determination)
• Food safety validation (e.g., pathogen enrichment per ISO 6579-1, thermal death time studies)
• Calibration of secondary temperature sensors (thermocouples, RTDs) against primary standards

FAQ

What is the minimum and maximum recommended working volume for optimal temperature uniformity?

For best thermal homogeneity, operate between 3.4 L and 25.5 L—the manufacturer-specified nominal range for the PURA22 model. Volumes below 3.4 L may reduce circulation efficiency; volumes above 25.5 L do not compromise stability but require extended equilibration time.

Can the PURA22 be used with glycerol/water mixtures or silicone oil?

No. The PURA22 is validated exclusively for aqueous media per DIN 12876-1 Class I. Use of viscous or low-conductivity fluids risks pump overload, uneven heating, and inaccurate sensor feedback.

Is external cooling capability available?

The PURA22 is a heating-only bath. For sub-ambient operation, consider Julabo’s F26 or FT40 refrigerated circulators, which support dual-range control from –25 °C to +150 °C.

Does the unit include calibration documentation?

Factory calibration certificates (traceable to DKD/DAkkS-accredited labs) are available upon request at time of order; they are not shipped by default but can be added as a no-cost option for regulated users.

How often should preventive maintenance be performed?

Julabo recommends annual inspection of the drain valve seal, visual verification of heater coil integrity, and cleaning of the circulation impeller housing—especially after use with hard water or salt solutions. Full service intervals are outlined in the Operation Manual (Doc. No. 9550522-EN).