LAUDA Alpha RA 24 External Circulation Refrigerated & Heated Bath Circulator (-25°C to 100°C, ±0.05°C Stability)

Overview

The LAUDA Alpha RA 24 is a precision-engineered refrigerated and heated bath circulator designed for demanding laboratory temperature control applications requiring stable, reproducible thermal environments across an extended range of –25 °C to +100 °C. Based on LAUDA’s proven Alpha platform, the RA 24 integrates a hermetically sealed scroll compressor, a high-efficiency immersion heater, and a continuously controlled centrifugal circulation pump into a compact, robust architecture. It operates using the thermodynamic principle of vapor-compression refrigeration combined with resistive heating—enabling seamless transition between cooling and heating modes without overshoot or hysteresis. The system is optimized for use with non-flammable heat transfer fluids, including water, aqueous glycol solutions, and ethanol, making it suitable for both internal bath temperature regulation and external jacketed reactor or instrument cooling/heating via closed-loop circulation. Its ±0.05 °C temperature stability—verified under ISO 17025-accredited calibration conditions—is achieved through a high-resolution Pt100 sensor, adaptive PID control logic, and intelligent thermal mass management.

Key Features

• Wide operational temperature span from –25 °C to +100 °C, covering >95% of routine lab thermal protocols including cryogenic sample conditioning, enzymatic reaction incubation, and high-temperature solvent-based extractions.
• Integrated dual-mode thermal actuation: energy-efficient R-134a compressor (GWP 1430, compliant with EU F-Gas Regulation No. 517/2014) paired with a 1.5 kW immersion heater ensures rapid ramp rates and minimal thermal lag.
• Intelligent compressor modulation—activated only when required—reduces mechanical wear, extends service life beyond 20,000 operating hours, and lowers total cost of ownership by up to 30% versus fixed-speed alternatives.
• Front-accessible condenser grille enables tool-free cleaning, minimizing downtime and supporting GLP-mandated preventive maintenance schedules.
• Stainless steel bath vessel (350 × 277 × 160 mm usable dimensions) with integrated level and overtemperature safety cutoffs, audible/visual alarms, and flow-reduction protection to prevent dry-run damage.
• Standard Ethernet interface (RJ45) supports remote monitoring and control via LAUDA’s LabView-compatible software suite; optional add-ons include analog I/O, flow meter integration, and speed-controlled pump modules.

Sample Compatibility & Compliance

The RA 24 is validated for use with non-flammable, low-viscosity heat transfer media—including deionized water, 30–50% v/v aqueous ethylene glycol, and anhydrous ethanol—ensuring compatibility with ASTM D1250, ISO 3104, and USP viscosity calibration standards. Its stainless steel bath and chemically resistant silicone tubing minimize leaching and corrosion, supporting long-term use in QC/QA labs subject to FDA 21 CFR Part 11 and EU Annex 11 requirements. All firmware includes audit-trail logging, user-level access controls, and electronic signature capability for regulated environments. The unit meets IEC 61010-1:2010 safety standards for laboratory equipment and carries CE marking per the Low Voltage Directive (2014/35/EU) and EMC Directive (2014/30/EU).

Software & Data Management

Control is executed via a three-button front-panel interface with a monochrome LED display showing real-time bath temperature, setpoint, and status indicators. For advanced operation, LAUDA’s proprietary AlphaControl software (Windows-based, USB/Ethernet supported) provides full parameter configuration—including ramp/soak profiles, alarm thresholds, pump speed curves, and data export in CSV or XML formats. The software supports automated compliance reporting aligned with ISO/IEC 17025 documentation requirements, including uncertainty budgeting for temperature stability (k=2). Optional integration with LIMS platforms is available via OPC UA or Modbus TCP protocols, enabling traceable data capture directly into ELN systems without manual transcription.

Applications

• Chemical synthesis: precise temperature control during exothermic Grignard reactions or low-T Diels–Alder cyclizations.
• Pharmaceutical QC: dissolution testing per USP , stability chamber validation, and reference standard storage at defined thermal setpoints.
• Materials science: thermal cycling of polymer composites, battery electrolyte characterization, and thin-film deposition substrate conditioning.
• Biotechnology: enzyme kinetics assays, cell culture media pre-warming, and cold-chain validation for diagnostic reagents.
• Electronics testing: thermal stress screening of PCB assemblies and semiconductor packaging under controlled ramp-and-hold profiles.

FAQ

What heat transfer fluids are certified for use with the RA 24?

Deionized water, 30–50% ethylene glycol/water mixtures, and anhydrous ethanol are fully supported. Mineral oil, silicone oil, and flammable solvents (e.g., acetone, methanol) are strictly prohibited.
Does the RA 24 support external temperature feedback control?

Yes—via optional PT100 input port, enabling cascade control using a probe placed directly in the sample or reactor, improving thermal uniformity beyond bath-setpoint accuracy.
Is the unit compatible with GMP/GLP documentation workflows?

Fully compliant: built-in event log, user authentication, electronic signatures, and 21 CFR Part 11–ready audit trail generation via AlphaControl software.
What is the minimum recommended fill volume for stable operation?

14.0 L (minimum bath fill) ensures adequate thermal mass and prevents premature activation of low-level safety cutoffs.
Can the RA 24 be integrated into a central lab automation network?

Yes—standard Ethernet connectivity supports SNMP monitoring, REST API access, and seamless integration with LabVantage, STARLIMS, and Benchling via middleware adapters.