JULABO AK40 High-Precision Temperature Calibration System
| Brand | JULABO |
|---|---|
| Origin | Germany |
| Model | AK40 / AK80 |
| Temperature Range | -40 °C to +250 °C |
| Temperature Stability | ±0.002 °C |
| Temperature Uniformity | ±0.01 °C |
| Bath Diameter | 118 mm |
| Bath Depth | 384 mm |
| Bath Volume | 7 L |
| Circulation Port | M24×1.5 |
Overview
The JULABO AK40 High-Precision Temperature Calibration System is a metrologically traceable, closed-loop liquid bath calibration platform engineered for primary and secondary temperature standardization in accredited laboratories, pharmaceutical QC environments, and national metrology institutes. It operates on the principle of dynamic liquid-bath thermoregulation using a high-stability, hermetically sealed circulation loop—where thermally conditioned silicone or mineral oil is continuously recirculated through a precision-machined stainless-steel calibration bath via an optimized overflow distribution system. This architecture eliminates vertical thermal stratification and minimizes transient lag, enabling stable, homogeneous temperature fields essential for calibrating PRTs (Platinum Resistance Thermometers), RTDs, thermistors, liquid-in-glass thermometers, and digital temperature probes per ISO/IEC 17025 requirements.
Key Features
- Stainless-steel calibration bath with symmetrical geometry and overflow-driven fluid distribution, ensuring axial and radial temperature uniformity of ±0.01 °C across the entire working volume
- Integrated PRESTO-based high-precision dynamic temperature control unit featuring ICC (Intelligent Control Circuit) technology, delivering long-term stability of ±0.002 °C at setpoint
- Hermetic sealing design prevents volatile bath fluid evaporation and vapor leakage—critical for extended operation at elevated temperatures and for compliance with laboratory safety protocols (e.g., OSHA 1910.1200)
- Dual-model configuration: AK40 supports -40 °C to +250 °C; AK80 extends low-temperature capability to -80 °C while maintaining identical upper limit and uniformity performance
- M24×1.5 metric circulation ports compatible with standardized external sensor immersion fixtures and automated calibration workstations
- Optimized thermal mass and insulation architecture enables rapid ramp rates (up to 3.5 °C/min from -40 °C to +100 °C) without compromising stability or introducing overshoot
Sample Compatibility & Compliance
The AK40 accommodates a wide range of temperature sensors up to 12 mm diameter and 350 mm immersion depth. Its 7 L bath volume and 118 mm aperture support multi-sensor simultaneous calibration under identical thermal conditions—enabling intercomparison studies per ASTM E74-22 and ISO 5725-2. The system is designed to meet the environmental control requirements of ISO/IEC 17025:2017 Clause 6.4.3 (environmental monitoring for calibration), and its thermal performance is validated against ITS-90 fixed points (e.g., gallium melt, water triple point) using reference standards traceable to NMIs such as PTB or NIST. Optional documentation packages include factory calibration certificates with uncertainty budgets compliant with EURAMET cg-18 and GUM (JCGM 100:2008).
Software & Data Management
While the AK40 operates as a standalone hardware platform, it integrates seamlessly with third-party calibration software suites (e.g., MET/CAL, DATACAL, WinQbase) via RS232, USB-CDC, or optional Ethernet interface. All temperature setpoints, ramp profiles, dwell times, and real-time bath sensor readings are accessible through ASCII protocol commands. Internal logging (optional SD card module) records timestamped bath temperature, controller status, and alarm events at user-defined intervals (1–60 s), supporting audit trails required under FDA 21 CFR Part 11 for electronic records in regulated pharmaceutical and medical device manufacturing. Full GLP/GMP-compliant reporting templates—including calibration certificates, uncertainty analysis, and deviation logs—are exportable in PDF and CSV formats.
Applications
- Primary calibration of industrial platinum resistance thermometers (PRTs) and SPRTs in metrology labs
- Validation of temperature-sensitive processes in pharmaceutical manufacturing (e.g., autoclave mapping, stability chamber qualification per ICH Q1A–Q1E)
- Verification of thermocouple reference junctions and cold-junction compensators
- Research-grade thermal characterization of phase-change materials and nanofluids
- Supporting ISO 17025 accreditation audits for temperature measurement capabilities
- Calibration of handheld thermometers, infrared sensors (via blackbody coupling), and data loggers used in environmental monitoring
FAQ
What is the recommended heat transfer fluid for operation across the full -40 °C to +250 °C range?
Silicone-based thermal oils meeting DIN 51519 Type K specifications (e.g., DC-200 or Syltherm XLT) are validated for continuous use within this span. Mineral oils are restricted to ≤150 °C.
Can the AK40 be used for calibration under ISO/IEC 17025 accreditation?
Yes—the system’s documented stability, uniformity, and traceable calibration path satisfy Clause 6.4.3 and Appendix B requirements when operated with certified reference thermometers and documented procedures.
Is remote monitoring and control supported?
Standard RS232 communication enables integration into LabVIEW, Python, or custom SCADA systems. Optional Ethernet module adds TCP/IP support for centralized lab-wide temperature asset management.
How often does the system require recalibration?
JULABO recommends annual verification of the internal Pt100 sensor against a certified reference thermometer; full system performance validation should align with your laboratory’s quality management schedule (typically every 6–12 months).
Does the overflow design affect bath fluid consumption or maintenance frequency?
No—the closed-loop overflow circuit recirculates >99.8% of fluid volume; typical top-up interval exceeds 18 months under continuous operation at 150 °C.
