Julabo FT400 Immersion Cooling Circulator

Overview

The Julabo FT400 Immersion Cooling Circulator is a compact, single-stage refrigerated circulator engineered for precise low-temperature control in laboratory-scale external systems. Unlike conventional bath circulators, the FT400 employs an immersion-style cooling head — a thermally optimized stainless-steel probe directly inserted into the process fluid — enabling rapid heat extraction without requiring a dedicated reservoir or large thermal mass. Its refrigeration system utilizes R404A, a zeotropic HFC blend selected for reliable performance across wide operating ranges and compatibility with standard hermetic compressors. The unit operates within a temperature range of –40 °C to +30 °C, making it suitable for applications demanding sub-ambient stabilization—such as cryogenic reaction monitoring, low-temperature spectroscopy sample conditioning, or controlled crystallization—without reliance on consumable cryogens like dry ice or liquid nitrogen. Designed for integration rather than standalone use, the FT400 functions as a cold-side complement to Julabo heating circulators (e.g., HL series), enabling full-range temperature programming when paired via external PID control or shared communication protocols.

Key Features

• Immersion-cooling architecture with high-efficiency stainless-steel cooling head (120 mm × Ø50 mm), minimizing thermal lag and maximizing heat transfer coefficient in direct-contact configurations
• Precision temperature control with 0.1 °C display resolution and factory-calibrated Pt100 sensor (included: 200 mm × Ø6 mm probe, 1.5 m PTFE-insulated cable)
• Compact footprint (20 × 30 × 43 cm) and low mass (24 kg), facilitating benchtop deployment in space-constrained analytical labs or fume hood environments
• Single-stage hermetic compressor with optimized oil management for stable operation at sustained low temperatures (down to –40 °C ambient-compensated)
• R404A refrigerant charge (184 g) balanced for performance and serviceability; global warming potential (GWP) documented per EN 378-1 for environmental compliance reporting
• Integrated safety logic including overtemperature cutoff, low-flow detection, and compressor discharge temperature monitoring

Sample Compatibility & Compliance

The FT400 is compatible with non-corrosive, low-viscosity liquids commonly used in laboratory thermal management—including water/ethylene glycol mixtures, silicone oils (up to 50 cSt), and low-aromatic hydrocarbon solvents. It is not rated for use with halogenated solvents, strong acids/bases, or particulate-laden suspensions. From a regulatory standpoint, the unit conforms to IEC 61010-1:2010 for electrical safety in laboratory equipment and meets EMC requirements per EN 61326-1:2013. While not intrinsically rated for hazardous locations, its sealed compressor and IP20-rated enclosure support general-purpose lab use under ISO/IEC 17025-accredited quality systems. Documentation includes full Declaration of Conformity (DoC), refrigerant handling data per F-Gas Regulation (EU) No 517/2014, and traceable calibration certificates for the integrated Pt100 sensor.

Software & Data Management

The FT400 operates via front-panel keypad and dual-line LCD interface; no embedded software stack or network connectivity is provided. However, its analog 0–10 V and digital RS232 interfaces enable integration into centralized lab automation frameworks. When connected to Julabo’s optional LabSoft software (v4.2+), users can log temperature profiles, configure ramp/soak cycles, and generate audit-trail-compliant reports aligned with FDA 21 CFR Part 11 requirements—including electronic signatures, user access levels, and immutable timestamped records. All temperature setpoints and actual values are logged with millisecond-level time stamps, supporting GLP/GMP traceability for method validation and equipment qualification (IQ/OQ/PQ).

Applications

• Low-temperature reaction calorimetry in pharmaceutical process development
• Cooling jacket control for rotary evaporators operating below ambient
• Thermal conditioning of NMR probe preamplifiers and detector housings
• Stabilization of optical benches and interferometric platforms sensitive to thermal drift
• Pre-cooling of samples prior to XRD or DSC analysis to minimize thermal history effects
• Integration into custom-built flow chemistry reactors requiring precise exotherm management

FAQ

Can the FT400 achieve –100 °C as mentioned in some legacy marketing materials?
No. The verified operational range is –40 °C to +30 °C. Claims of –100 °C refer to obsolete FT-series variants (e.g., FT902 with cascade configuration) no longer in production.
Is the included Pt100 sensor suitable for calibration against NIST-traceable standards?
Yes—the supplied Class A Pt100 sensor is individually calibrated with uncertainty ≤ ±0.15 °C at 0 °C and includes a certificate of conformity referencing DIN EN 60751.
What maintenance intervals are recommended for long-term reliability?
Compressor oil inspection every 24 months; condenser coil cleaning quarterly in dusty environments; refrigerant leak verification annually per ISO 5149-2.
Can the FT400 be operated continuously at –40 °C ambient temperature?
No. Ambient operating limits are strictly 5–35 °C per IEC 60068-2-1/2; operation outside this range invalidates warranty and risks compressor oil viscosity failure.
Does Julabo provide IQ/OQ documentation packages for regulated laboratories?
Yes—validated protocol templates, blank execution forms, and instrument-specific test scripts are available upon request through Julabo’s Regulatory Support Team (certified to ISO 13485 and ISO 9001).