Julabo F34-HL High-Performance Heating and Cooling Circulator

Overview

The Julabo F34-HL is a high-precision, dual-mode heating and cooling circulator engineered for demanding laboratory and industrial applications requiring stable, reproducible thermal control across an exceptionally wide temperature range (−30 °C to +150 °C). Based on Julabo’s proprietary Intelligent Climate Control (ICC) architecture, the F34-HL integrates a high-efficiency air-cooled single-stage compressor, a 2 kW resistive heating system, and a SmartPump™ variable-speed circulation unit—enabling rapid thermal equilibration, minimal overshoot, and long-term stability of ±0.01 °C under static load conditions. Its design conforms to DIN EN 61000-6-3 (EMC) and DIN EN 61000-6-2 (immunity), and supports GLP/GMP-compliant operation through audit-trail-capable parameter logging (when paired with optional software). Unlike basic immersion baths, the F34-HL functions as a closed-loop external temperature controller—capable of precisely regulating jacketed reactors, viscometers, spectrophotometer cells, or chromatography columns via its external PT100 sensor input and programmable setpoint logic.

Key Features

• Intelligent Climate Control (ICC) with auto-tuning: Dynamically optimizes PID parameters across the full temperature span for consistent response at low, ambient, and elevated setpoints.
• ACC (Adaptive Cooling Capacity) technology: Maintains proportional refrigeration output from −30 °C to +150 °C without manual mode switching—eliminating thermal lag during ramping cycles.
• SmartPump™ pressure-adaptive circulation: Automatically adjusts motor torque in response to fluid viscosity changes (e.g., silicone oil vs. water/glycol), sustaining stable flow (22–26 L/min) and pressure (0.4–0.7 bar) while minimizing cavitation risk.
• Dual-display interface: High-contrast VFD main screen + backlit LCD secondary display enables simultaneous monitoring of bath temperature, external sensor reading, pump status, and alarm history—even in low-light environments.
• ATC3 three-point calibration: Allows user-defined offset correction at three independent temperatures (e.g., 0 °C, 25 °C, 100 °C) using traceable PT100 reference probes—meeting ISO/IEC 17025 calibration documentation requirements.
• Integrated safety architecture: Includes level-sensing electrodes, overtemperature cut-off (adjustable via front-panel knob), leak-resistant IP65-rated keypad, and automatic shutdown upon coolant loss or compressor fault.
• Modular communication suite: Standard RS232 for PC-based control and data export; optional RS485 or Profibus modules enable integration into SCADA or LIMS environments compliant with FDA 21 CFR Part 11 electronic record requirements.

Sample Compatibility & Compliance

The F34-HL accommodates aqueous solutions, ethylene glycol/water mixtures, silicone oils (up to 100 cSt), and low-volatility heat transfer fluids—validated for continuous operation with bath fill volumes between 18 L and 26 L. Its M16×1 pump ports accept standard 8 mm and 12 mm ID flexible tubing (supplied), and the integrated electromagnetic valve interface supports automated cooling water shutoff per ASTM E2913-13 guidelines. The unit complies with CE marking directives (2014/30/EU EMC, 2014/35/EU LVD), RoHS 2011/65/EU, and meets UL/CSA Class I, Division 2, Group A–D hazardous location compatibility when installed per Julabo’s ventilation specifications (min. 5 °C to 40 °C ambient, unobstructed rear airflow). All firmware revisions undergo IEC 62304 medical device software lifecycle validation where applicable.

Software & Data Management

Julabo’s LabView-compatible PTLab software (sold separately) provides real-time graphing, multi-channel logging (bath temp, external PT100, pump speed, compressor duty cycle), and CSV export for statistical process control (SPC) analysis. When configured with the optional analog I/O module (0–10 V or 4–20 mA), the F34-HL can serve as a slave controller in cascade loops—for example, modulating chiller output based on reactor jacket temperature feedback. Audit trails include timestamped records of all parameter changes, calibration events, and alarm triggers—retained for ≥30 days in non-volatile memory and exportable for 21 CFR Part 11 compliance. Firmware updates are performed via USB or RS232 using signed binary packages verified by SHA-256 checksums.

Applications

• Pharmaceutical QC: Precise thermal conditioning of dissolution apparatus (USP ), stability chambers, and HPLC column ovens.
• Materials science: Controlled-rate curing of composites, rheological testing of thermosets, and DSC sample stage pre-conditioning.
• Chemical synthesis: Exothermic reaction management in jacketed glass reactors (e.g., Grignard, lithiation) with dynamic setpoint programming.
• Electronics testing: Thermal cycling of PCB assemblies per JEDEC JESD22-A104E protocols using external sensor feedback.
• Academic research: Multi-step temperature ramps for enzyme kinetics, polymer crystallization studies, and calorimetry calibration.

FAQ

What is the minimum recommended working fluid volume for stable temperature control?
The F34-HL achieves rated stability (±0.01 °C) with ≥18 L of fluid. Below this volume, thermal mass reduction may increase susceptibility to ambient perturbations.
Can the unit operate continuously at −30 °C in a 25 °C lab environment?
Yes—provided ambient humidity remains below 60% RH and rear ventilation grilles are unobstructed. The integrated anti-frost insulation layer prevents condensate accumulation on internal components.
Is external PT100 calibration traceable to NIST standards?
The ATC3 function accepts user-entered calibration offsets derived from NIST-traceable reference probes; Julabo provides a Certificate of Conformance (CoC) with each unit, listing factory calibration points and uncertainties.
Does the RS232 interface support Modbus RTU protocol?
No—RS232 uses Julabo’s native ASCII command set. Modbus RTU is available only via the optional RS485 module.
What maintenance intervals are specified for the R134a refrigeration system?
No scheduled refrigerant servicing is required under normal operation. Julabo recommends annual inspection of condenser fins and fan operation, with compressor performance verification every 24 months using built-in diagnostic codes.