Julabo FW95-SL Ultra-Low Temperature Circulating Bath Chiller

Overview

The Julabo FW95-SL is an ultra-low temperature circulating bath chiller engineered for precision thermal control in demanding laboratory and industrial applications requiring stable operation down to −95 °C. It employs a single-stage, water-cooled R404A refrigeration system combined with high-efficiency resistive heating elements to deliver bidirectional temperature control across its full operating range. The unit operates on the principle of forced liquid circulation—pumping thermally conditioned fluid through an internal bath or external process loop—to maintain uniform thermal conditions with minimal drift. Its design adheres to DIN 12876-1 Class III (FL) safety standards for flammable liquids, making it suitable for use with low-flashpoint solvents in cryogenic reaction setups, material testing, and analytical instrument cooling. The integrated water-cooling architecture eliminates reliance on ambient air for heat rejection, enabling consistent performance even in elevated ambient temperatures up to 40 °C.

Key Features

• VFD white-backlit display with simultaneous real-time readout of bath temperature, setpoint, external sensor input, pump pressure, and system status
• Intelligent ICC (Intelligent Control Concept) auto-tuning algorithm that dynamically optimizes PID parameters for improved stability across wide temperature transitions
• TCF (Temperature Control Function) technology for enhanced response during rapid ramping or load changes
• ATC3 three-point calibration routine supporting traceable adjustment using external reference probes
• SmartPump variable-speed circulation system automatically modulates motor output based on fluid viscosity and system backpressure, ensuring consistent flow from −95 °C to 0 °C
• Removable front air grille and accessible condenser coil for routine maintenance without disassembly
• Dual-level liquid level monitoring with audible/visual alert and automatic shutdown upon low-bath detection
• Integrated electromagnetic valve interface for coordinated control of auxiliary cooling water supply and high-static-pressure (HSP) booster pumps
• RS232 serial port standard; optional RS485 or Profibus modules available for integration into centralized lab automation networks
• Onboard 6×60-step programmable temperature profile controller with ramp/soak functionality

Sample Compatibility & Compliance

The FW95-SL accommodates both internal bath immersion and external closed-loop applications via dual M16×1 pump ports (with included 8 mm and 12 mm hose barbs) and a G3/4″ male cooling water inlet. Its stainless steel bath chamber and fluoropolymer-sealed components ensure chemical compatibility with common organic solvents, silicone oils, and glycol-water mixtures used at subzero temperatures. The unit conforms to DIN 12876-1 Class III (FL), certifying safe operation with flammable media under defined ventilation and containment conditions. Electrical safety complies with IEC 61010-1. While not intrinsically rated for hazardous areas, its design supports integration into GLP- and GMP-regulated environments when paired with audit-trail-capable software and validated operational protocols.

Software & Data Management

The built-in RS232 interface enables direct communication with Windows-based host systems using Julabo’s proprietary LabView-compatible drivers or third-party SCADA platforms. All temperature setpoints, ramp rates, alarm thresholds, and calibration data are stored non-volatily. When connected to compliant software, the system supports time-stamped event logging—including temperature excursions, pump faults, refrigerant pressure anomalies, and user-initiated parameter changes—meeting basic requirements for FDA 21 CFR Part 11 electronic record integrity where local validation is performed. Optional analog I/O modules provide 0–10 V or 4–20 mA outputs for external PLC interfacing or legacy DCS integration.

Applications

• Cryogenic reaction control in pharmaceutical synthesis and fine chemical manufacturing
• Thermal conditioning of NMR probe pre-cooling circuits and mass spectrometer ion sources
• Material property evaluation (e.g., tensile strength, ductility, phase transition behavior) across extreme low-temperature ranges
• Calibration of low-temperature sensors and reference thermometers per ISO/IEC 17025 requirements
• Stabilization of laser diodes and quantum optics instrumentation requiring sub-0.1 °C thermal uniformity
• Environmental stress screening of aerospace composites and electronics packaging

FAQ

What is the minimum achievable temperature with the FW95-SL?
The unit achieves a stable operating temperature of −95 °C under nominal load conditions with recommended heat transfer fluids (e.g., 50/50 ethylene glycol/water or specialized low-temperature oils).
Is external cooling water required for operation?
Yes—the FW95-SL uses a water-cooled condenser; continuous supply of clean, deionized water at 10–30 °C and ≥3 bar pressure is mandatory for rated refrigeration capacity.
Can the FW95-SL be used with flammable solvents?
It is certified to DIN 12876-1 Class III (FL), permitting use with flammable liquids provided appropriate engineering controls (e.g., explosion-proof enclosures, inert gas purging) and procedural safeguards are implemented.
Does the unit support remote monitoring and control via Ethernet?
Standard configuration includes RS232 and RS485; Ethernet connectivity requires optional gateway hardware and firmware upgrade.
How often does the refrigerant require servicing?
R404A charge is sealed for life under normal operation; periodic leak checks per ISO 5149 are recommended annually, with recharging only necessary following verified loss events.