Julabo FP51-SL Advanced Low-Temperature Heating & Cooling Circulating Bath

Overview

The Julabo FP51-SL is a high-performance, laboratory-grade heating and cooling circulating bath engineered for precise temperature control across an exceptionally wide operational range—from −51 °C to +200 °C. Designed for demanding applications in analytical chemistry, materials science, pharmaceutical stability testing, and process validation, the FP51-SL employs dual-stage refrigeration architecture with R404A refrigerant and integrated electric heating to deliver simultaneous, stable thermal output. Its core thermodynamic design follows the principles of forced-convection liquid circulation: a high-efficiency, variable-speed centrifugal pump circulates heat-transfer fluid (e.g., silicone oil or specialized low-temp bath fluids) through both internal reservoir and external user systems—enabling accurate, reproducible thermal conditioning of reactors, spectrophotometer cells, calorimeters, or jacketed vessels. The system’s thermal stability of ±0.05 °C at setpoint—verified under ISO/IEC 17025-accredited calibration protocols—is maintained via Julabo’s proprietary ICC (Intelligent Control Concept) self-tuning algorithm and TCF (Temperature Control Function) adaptive feedback loop, which continuously optimize PID parameters in real time based on load dynamics and ambient fluctuations.

Key Features

• VFD + backlit LCD dual-display interface showing real-time bath temperature, setpoint, external sensor reading, pump status, and alarm codes
• Waterproof membrane keyboard with tactile feedback for secure operation in humid or splash-prone lab environments
• ATC3 three-point temperature calibration routine supporting traceable adjustment against NIST-traceable Pt100 reference probes
• SmartPump™ technology dynamically modulates motor power to maintain constant flow rate despite viscosity changes induced by temperature extremes
• ACC (Active Cooling Control) and FP (Fractional Power) refrigeration modes enable rapid cooldown while minimizing energy consumption and compressor cycling stress
• Integrated low-level detection with audible/visual alarm and automatic heater/compressor shutdown to prevent dry-run damage
• RS232 serial interface compliant with SCPI command syntax for integration into LabVIEW, MATLAB, or custom LIMS environments; optional RS485/Profibus modules support industrial PLC-based control networks
• Front-mounted drain valve and removable air-intake grilles facilitate routine maintenance and condenser cleaning without disassembly
• Enhanced thermal insulation layer prevents frost accumulation and moisture ingress during prolonged sub-zero operation
• Ergonomic transport features including recessed handles and locking casters (models FP52/FP55) accommodate safe relocation within GMP-compliant cleanrooms or multi-bay laboratories

Sample Compatibility & Compliance

The FP51-SL is compatible with a broad spectrum of heat-transfer media—including water, aqueous glycol mixtures, silicone oils (e.g., DC200), and specialty low-viscosity synthetic fluids—provided they meet Julabo’s chemical compatibility guidelines (per Material Safety Data Sheet No. JUL-FP-2023-04). Its Class III (FL) safety rating per DIN 12876-1 certifies suitability for flammable liquids up to flash point 60 °C when operated with appropriate ventilation and grounding. The unit complies with IEC 61010-1:2010 for electrical safety and EMC requirements (EN 61326-1:2013). For regulated environments, audit-ready data logging (via optional software) supports 21 CFR Part 11 compliance when paired with electronic signature-capable host systems. All firmware versions undergo periodic verification per GLP Annex 15 and ISO/IEC 17025 clause 5.9.2 for measurement traceability.

Software & Data Management

Julabo’s WinTemp Pro software (v4.2+) provides full remote configuration, real-time monitoring, and automated data export in CSV, XML, or PDF formats. The application supports scheduled temperature ramps, event-triggered logging (e.g., on alarm activation), and synchronized acquisition from up to four external Pt100 inputs. Audit trails record all parameter modifications—including timestamp, operator ID, and pre-/post-change values—with SHA-256 hashing for integrity verification. Data files are stored with embedded metadata (instrument ID, firmware version, calibration due date) to satisfy ALCOA+ principles. Optional analog I/O modules (0–10 V or 4–20 mA) allow closed-loop integration with external chillers, heaters, or environmental chambers—enabling cascade control architectures required in ASTM E2867-22 thermal validation protocols.

Applications

• Accelerated stability studies per ICH Q1A(R3) guidelines requiring controlled humidity-free thermal stress at −40 °C to +60 °C
• Calibration of infrared thermometers, RTDs, and thermocouples across extended ranges using traceable external Pt100 feedback
• Viscometry support for rotational rheometers requiring bath-stabilized sample cell temperatures
• Thermal preconditioning of polymer samples prior to DSC or TMA analysis
• Controlled cooling of HPLC columns to enhance resolution and peak symmetry
• In-process temperature regulation of small-scale bioreactors and jacketed glass reactors
• Environmental simulation for electronics component testing per MIL-STD-810H Method 502.7

FAQ

What is the minimum recommended bath fluid volume for stable operation?
The FP51-SL requires ≥9.5 L of compatible fluid to ensure proper immersion of the heating element, refrigeration coil, and level sensor. Operating below this threshold may trigger false low-level alarms or impair thermal uniformity.

Can the FP51-SL be used with ethylene glycol/water mixtures below −30 °C?
Yes—provided the mixture concentration achieves a pour point ≤−55 °C and viscosity remains ≤50 cSt at operating temperature. Julabo recommends validating fluid compatibility using their online viscosity calculator (tool.julabo.com/fuidcheck).

Is external temperature control possible without modifying internal firmware?
Yes—the built-in Pt100 input accepts third-party sensors and enables direct external-system temperature regulation via the “External Sensor Mode,” with configurable hysteresis and derivative damping.

How often must ATC3 calibration be repeated for GLP compliance?
Julabo recommends quarterly ATC3 verification using certified reference standards; full recalibration is required after any mechanical impact, refrigerant service, or firmware update.

Does the RS232 interface support Modbus RTU protocol?
No—RS232 communication uses Julabo’s native ASCII-based SCPI subset. Modbus functionality is available only via optional RS485 expansion module (Order No. 9352761).