Julabo F95-SL Ultra-Low Temperature Circulating Bath Chiller

Overview

The Julabo F95-SL Ultra-Low Temperature Circulating Bath Chiller is a dual-stage, air-cooled laboratory temperature control system engineered for precise, stable, and reproducible thermal management across extreme low-temperature applications. Designed and manufactured in Germany, it integrates two independent refrigeration circuits—R404A for the high-stage and R23 for the ultra-low-stage—to achieve a continuous operational range from −95 °C to 0 °C. Unlike single-stage chillers limited by thermodynamic constraints at cryogenic temperatures, the F95-SL employs cascade refrigeration architecture to maintain high cooling capacity even below −80 °C. Its core function is to deliver tightly regulated, recirculated heat-transfer fluid (e.g., ethanol/water or silicone oil mixtures) to external equipment—including reaction jackets, condensers, spectrometers, and material testing fixtures—while simultaneously supporting internal bath applications requiring sub-zero stability. The system conforms to DIN 12876-1 Class III (FL) safety requirements for flammable liquid handling, ensuring structural integrity, leak containment, and electrical protection in demanding lab environments.

Key Features

• VFD white-backlit display with simultaneous real-time readout of bath temperature, setpoint, external PT100 sensor reading, pump pressure, and system status
• Intelligent ICC (Intelligent Control Circuit) auto-tuning algorithm that dynamically optimizes PID parameters based on thermal load and fluid viscosity
• TCF (Temperature Control Function) mode for enhanced suppression of overshoot during rapid cooldown or heating transitions
• ATC3 three-point calibration support for traceable accuracy verification using external reference probes (e.g., certified Pt100 or PRT standards)
• SmartPump variable-speed circulation technology: automatically adjusts motor torque to maintain constant flow rate despite viscosity changes induced by temperature shifts
• Dual-level liquid level monitoring with audible/visual alert and automatic shutdown upon low-fluid detection
• Removable front air-intake grille for routine condenser maintenance without tools or disassembly
• Integrated electromagnetic valve interface for synchronized control of auxiliary cooling water supply and HSP high-static-pressure booster pumps
• RS232 serial port standard; optional RS485 or Profibus modules available for integration into centralized LabVantage or DeltaV control systems
• 6×60-step programmable temperature ramping profile memory for unattended multi-phase experiments (e.g., cryo-curing, polymer crystallization studies)

Sample Compatibility & Compliance

The F95-SL accommodates a broad spectrum of heat-transfer media, including aqueous glycol solutions (down to −50 °C), ethanol/water blends (−80 °C), and specialized low-viscosity silicone oils (−95 °C). Its stainless-steel bath chamber and fluoropolymer-sealed pump head resist corrosion from organic solvents and halogenated coolants. All wetted materials comply with USP Class VI biocompatibility requirements. From a regulatory standpoint, the unit supports GLP/GMP workflows through audit-trail-capable software logging (when paired with Julabo’s WinTherm software), configurable alarm thresholds per ISO/IEC 17025 clause 5.4.3, and hardware-enforced safety interlocks aligned with IEC 61010-1 Ed.3 for laboratory electrical equipment. Its dual-refrigerant design meets EU F-Gas Regulation (EU No 517/2014) reporting thresholds, with documented CO₂-equivalent emissions (9.546 t CO₂-eq total) provided in the Declaration of Conformity.

Software & Data Management

Julabo WinTherm PC software (Windows-compatible) enables remote configuration, real-time data streaming, and event-driven logging—including timestamped temperature deviations, pump fault codes, and refrigerant pressure anomalies. Data export is supported in CSV and XML formats for downstream analysis in MATLAB, JMP, or LIMS platforms. When deployed with optional analog I/O modules (0–10 V / 4–20 mA), the F95-SL functions as a field device within larger SCADA architectures, accepting setpoint overrides and transmitting process variables via Modbus RTU over RS485. All communication protocols adhere to FDA 21 CFR Part 11 Annex 11 principles: user authentication, electronic signatures, and immutable log records with SHA-256 hashing are implemented at firmware level.

Applications

• Cryogenic reaction calorimetry in pharmaceutical process development (ICH Q5C stability studies at −40 °C)
• Low-temperature material testing per ASTM D746 (impact brittleness of polymers at −70 °C)
• Controlled condensation in vacuum distillation setups requiring −85 °C cold traps
• Calibration of infrared detectors and bolometers under stabilized sub-zero blackbody conditions
• Thermal cycling of aerospace composites per MIL-STD-810H Method 502.7
• Superconductivity research requiring stable bath temperatures within ±0.03 °C at −90 °C

FAQ

What is the minimum achievable temperature with standard heat-transfer fluids?
With 30% ethanol/70% deionized water, the F95-SL reliably maintains −80 °C; for −95 °C operation, Julabo recommends Therminol VP-1 or similar low-vapor-pressure silicone-based fluids.
Does the unit support external temperature feedback control?
Yes—integrated Pt100 input accepts 2-, 3-, or 4-wire probes for direct measurement and closed-loop regulation of external jacket or reactor temperatures.
How is refrigerant leakage risk mitigated in dual-stage systems?
Each stage features hermetically sealed compressors with welded refrigerant lines, pressure sensors with automatic shutdown at >10% deviation from nominal charge, and annual leak-check ports compliant with EN 378-1.
Can the F95-SL be integrated into a building management system (BMS)?
Via optional Profibus-DP or Modbus TCP gateway modules, enabling status reporting, setpoint modulation, and predictive maintenance alerts through BACnet/IP or LonWorks interfaces.
Is validation documentation available for IQ/OQ protocols?
Julabo provides factory-verified calibration certificates (traceable to PTB), FAT/SAT checklists, and URS-mapped test scripts compatible with Annex 15 and GAMP5 frameworks.