Julabo FT402 Immersion Cooling Circulator
| Brand | Julabo |
|---|---|
| Origin | Germany |
| Model | FT402 |
| Temperature Range | −40 °C to +30 °C |
| Temperature Stability | ±0.5 °C |
| Temperature Resolution | 0.1 °C |
| Cooling Power (at 20 °C ambient) | 0.45 kW |
| Cooling Power (at −40 °C bath temp) | 0.03 kW |
| Refrigerant | R404A (230 V/50 Hz) or R134a (115 V/60 Hz) |
| Compressor Type | Single-stage, air-cooled |
| Cooling Head Material | Stainless steel (12 cm × 5 cm L × Ø) |
| Immersion Probe | PT100, 200 mm × Ø6 mm, 1.5 m cable, stainless steel sheath |
| Dimensions (W × L × H) | 20 × 30 × 43 cm |
| Weight | 24 kg |
| GWP of R404A | 3922 |
| CO₂-equivalent emissions per unit | 0.722 t |
Overview
The Julabo FT402 Immersion Cooling Circulator is a compact, high-efficiency cryogenic thermostat engineered for precise low-temperature control in laboratory-scale liquid systems. Unlike conventional recirculating chillers with external heat exchangers, the FT402 employs an integrated immersion cooling head — directly submerged into the process fluid — to deliver targeted thermal energy extraction. Its thermodynamic architecture is based on single-stage vapor-compression refrigeration using environmentally regulated refrigerants (R404A for 230 V/50 Hz operation; R134a for 115 V/60 Hz), enabling stable operation across a working range of −40 °C to +30 °C. The system achieves ±0.5 °C temperature stability under steady-state conditions and offers 0.1 °C digital resolution via LED display. Designed for integration into closed-loop applications — including jacketed reactors, spectroscopic sample cells, and cryogenic reaction vessels — the FT402 eliminates reliance on consumable cryogens such as dry ice or liquid nitrogen, supporting reproducible, GLP-aligned experimental protocols.
Key Features
- Direct immersion cooling head fabricated from electropolished stainless steel (12 cm × Ø5 cm), ensuring corrosion resistance and thermal conductivity consistency in aqueous, organic, and mildly aggressive media
- Digital PID temperature controller with front-panel LED interface, enabling setpoint programming and real-time monitoring without external software dependency
- Integrated PT100 temperature sensor (200 mm × Ø6 mm, 1.5 m PTFE-insulated cable, stainless steel sheath) supplied as standard for accurate external bath feedback
- Air-cooled, single-stage hermetic compressor with low-vibration mounting — suitable for benchtop deployment in ISO Class 5–7 laboratory environments
- Compact footprint (20 × 30 × 43 cm) and 24 kg mass facilitate installation in space-constrained fume hoods or modular lab setups
- Refrigerant selection automatically aligned with regional voltage/frequency standards to ensure compliance with EN 378-1 and IEC 60335-2-89 safety directives
Sample Compatibility & Compliance
The FT402 is compatible with non-pressurized liquid volumes up to 20 L when used with appropriate bath vessels (e.g., glass Dewar flasks, stainless steel jackets, or polymer-lined reactors). It supports common solvents including methanol, ethanol, acetone, ethylene glycol/water mixtures, and silicone oils — provided viscosity remains below 100 mPa·s at operating temperature. The unit conforms to European CE marking requirements under the Low Voltage Directive (2014/35/EU) and Electromagnetic Compatibility Directive (2014/30/EU). Refrigerant handling complies with F-Gas Regulation (EU) No. 517/2014, and full technical documentation — including Declaration of Conformity and refrigerant charge records — is provided for audit readiness in ISO/IEC 17025-accredited laboratories.
Software & Data Management
While the FT402 operates autonomously via its embedded controller, optional analog (0–10 V) and digital (RS232) interfaces enable connection to centralized lab monitoring systems (e.g., LabVIEW, DeltaV, or custom SCADA platforms). Temperature logging can be implemented externally using third-party DAQ hardware with timestamped PT100 input support. All firmware revisions maintain backward compatibility and are validated per IEC 62304 for medical-grade software lifecycle management. Audit trail functionality — including operator ID, setpoint changes, and alarm events — is available when integrated with compliant LIMS or ELN platforms adhering to FDA 21 CFR Part 11 requirements.
Applications
- Cryogenic reaction control in organic synthesis (e.g., lithiation, Grignard, and Diels–Alder reactions requiring sub-zero initiation)
- Stabilization of temperature-sensitive biomolecules during UV-Vis, fluorescence, or CD spectroscopy
- Calibration of low-temperature sensors and transducers against NIST-traceable references
- Pre-cooling of samples prior to X-ray diffraction or cryo-EM grid preparation
- Thermal conditioning of electrochemical cells in battery R&D workflows
- Integration with Julabo heating circulators (e.g., HL Series) to extend operational range into dual-temperature modulation regimes
FAQ
What is the minimum recommended bath volume for stable temperature control?
A minimum working volume of 3 L is advised to ensure adequate thermal mass and minimize overshoot during rapid setpoint transitions.
Can the FT402 be operated continuously at −40 °C?
Yes — continuous operation at −40 °C is supported under ambient conditions of 5–35 °C and relative humidity ≤70 % RH, provided condensate drainage and ventilation meet manufacturer-specified clearances.
Is the PT100 sensor included calibrated and certified?
The supplied PT100 probe meets DIN EN 60751 Class B tolerance (±0.3 °C at 0 °C); full calibration certificate (ISO/IEC 17025 accredited) is available upon request at time of order.
Does the unit support remote start/stop via digital signal?
Yes — the RS232 interface supports ASCII command protocol for remote activation, deactivation, setpoint adjustment, and status polling.
What maintenance intervals are recommended for long-term reliability?
Compressor oil inspection every 24 months; condenser coil cleaning every 6 months in dust-prone environments; annual verification of refrigerant charge integrity using manifold gauge set and leak detection per EN 15603.
