Julabo FP90-SL Ultra-Low Temperature Heating and Cooling Circulating Bath

Overview

The Julabo FP90-SL is an ultra-low temperature heating and cooling circulating bath engineered for precision thermal control in demanding laboratory and industrial applications. Utilizing a two-stage cascade refrigeration system with R404A (first stage) and R23 (second stage), the FP90-SL achieves stable operation down to –90 °C — a capability critical for cryogenic material testing, low-temperature reaction kinetics, superconductivity studies, and calibration of ultra-low temperature sensors. Its integrated heating element (3 kW) enables seamless transition across a continuous range from –90 °C to +100 °C, eliminating the need for separate heating and cooling units. The system employs Julabo’s proprietary ACC (Active Cold Control) and FP (Fractional Power) refrigeration management algorithms to deliver responsive, energy-efficient cooling across the full span — particularly vital at extreme sub-zero setpoints where conventional single-stage systems fail or exhibit poor stability. Temperature uniformity is maintained within ±0.05 °C via high-resolution PID control with ICC (Intelligent Control Cycle) self-tuning and TCF (Temperature Control Function) optimization, ensuring reproducibility required for GLP-compliant validation protocols and ISO/IEC 17025-accredited testing environments.

Key Features

• VFD white-backlit display with simultaneous readout of bath temperature, setpoint, external sensor reading, and system status
• Waterproof membrane keyboard with tactile feedback for secure parameter entry under lab conditions
• ATC3 three-point temperature calibration function traceable to NIST-certified standards
• SmartPump technology: automatic adjustment of pump power based on fluid viscosity and flow resistance, maintaining consistent delivery pressure (0.4–0.7 bar) and flow rate (22–26 L/min)
• Integrated low-level detection with audible/visual alarm and automatic heater/compressor shutdown
• RS232 standard interface; optional RS485 and Profibus modules for integration into SCADA or LIMS platforms
• External Pt100 input channel enabling direct feedback control of remote process jackets or reactors
• Electromagnetic valve interface for coordinated activation of auxiliary cooling water solenoids or HSP high-static-pressure pumps
• Removable front air grille and optimized condenser layout for routine maintenance without disassembly
• Dual-layer vacuum-insulated bath chamber minimizing frost formation and heat ingress at –90 °C operation

Sample Compatibility & Compliance

The FP90-SL accommodates a wide range of heat transfer media — including silicone oils, ethylene glycol/water mixtures, and specialized low-temperature fluids — via its 22 L stainless-steel reservoir and M16×1 pump ports (supplied with 8 mm and 12 mm hose fittings). Its DIN 12876-1 Class III (FL) certification confirms suitability for flammable liquids up to flash point 60 °C, supporting safe operation with organic solvents in chemical synthesis workflows. All electronic controls comply with IEC 61000-6-3 (EMC emission) and IEC 61000-6-2 (immunity) standards. Data logging and remote command execution meet FDA 21 CFR Part 11 requirements when paired with Julabo’s certified software suite, providing full audit trail, electronic signature support, and user-access-level configuration — essential for pharmaceutical QC labs operating under cGMP guidelines.

Software & Data Management

The FP90-SL supports native communication via ASCII protocol over RS232, enabling real-time monitoring and scripting in LabVIEW, MATLAB, or Python-based automation frameworks. Optional Julabo WinControl software provides full GUI-based operation, including 6×60-step programmable temperature ramps, event-triggered data export (CSV/TXT), and synchronized multi-channel logging (bath temp, external Pt100, compressor status, error codes). Audit logs record all parameter changes, user logins, alarm events, and calibration actions with timestamps and operator IDs — fully compliant with ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available). Firmware updates are performed via USB port with cryptographic signature verification to ensure integrity.

Applications

• Cryogenic characterization of polymers, composites, and battery electrolytes per ASTM D746 and ISO 974
• Low-temperature enzymatic assays and protein folding studies requiring sustained –80 °C stability
• Calibration of thermocouples, RTDs, and infrared sensors across extended ranges (–90 °C to +100 °C)
• Thermal cycling of electronic components per JEDEC JESD22-A104
• Temperature-controlled chromatography column ovens and detector housings
• Reaction calorimetry with external jacketed reactors using external Pt100 feedback
• Material stress testing under controlled thermal gradients per ISO 6721-1

FAQ

What is the minimum achievable temperature with the FP90-SL, and how long does it take to reach –90 °C from ambient?
The FP90-SL achieves –90 °C under standard lab conditions (23 °C ambient, dry air). Time-to-target depends on heat load and fluid type; with 22 L of silicone oil (c_p ≈ 1.67 J/g·K), cooling from 20 °C to –90 °C typically requires 180–220 minutes.
Does the FP90-SL support external temperature control using a process sensor?
Yes — it features a dedicated Pt100 input channel enabling closed-loop control of external systems (e.g., reactor jackets), with selectable control mode (bath vs. external sensor) and configurable PID parameters.
Is the unit suitable for use with flammable heat transfer fluids?
Yes — certified to DIN 12876-1 Class III (FL), it is approved for use with fluids having flash points ≥60 °C, provided proper ventilation and grounding are implemented per local safety regulations.
Can the FP90-SL be integrated into a centralized building management system (BMS)?
Via optional RS485 or Profibus modules, the unit supports Modbus RTU or Profibus DP protocols for interoperability with industrial BMS and PLC networks.
What maintenance intervals are recommended for the dual-stage refrigeration system?
Julabo recommends annual inspection of condenser cleanliness, refrigerant charge verification, and compressor oil analysis. The air-cooled design eliminates water-side scaling concerns but requires quarterly visual inspection of intake grilles for dust accumulation.