LabTech ES35A Pro Series Magnetic Stirrer with Heating

Overview

The LabTech ES35A Pro Series Magnetic Stirrer with Heating is an integrated benchtop laboratory instrument engineered for precise, reproducible agitation and temperature-controlled sample conditioning in analytical, quality control, and research environments. It operates on the principle of magnetic coupling—where a rotating permanent magnet beneath the heated plate induces synchronous rotation of a magnetically responsive stir bar immersed in the sample vessel. This non-contact drive mechanism eliminates mechanical shaft seals and bearing wear, ensuring long-term operational stability and contamination-free mixing. The unit combines a high-efficiency resistive heating system with closed-loop electronic speed regulation, enabling simultaneous control of thermal and hydrodynamic parameters across a wide dynamic range—from low-viscosity aqueous solutions to moderately viscous organic media. Designed for routine use in ISO/IEC 17025-accredited laboratories, pharmaceutical QC labs, and university teaching facilities, the ES35A Pro meets fundamental requirements for GLP-compliant method execution where traceable, repeatable stirring and heating profiles are essential.

Key Features

• Electronically regulated DC motor with real-time speed feedback, maintaining set RPM within ±2% deviation even under variable load conditions (e.g., viscosity changes during polymer dissolution or temperature-induced density shifts)
• Heating plate with precision-machined aluminum alloy surface and embedded Pt100 RTD sensor, delivering uniform thermal distribution across the working area and supporting stable temperature control from ambient up to 340 °C
• Dual-safety architecture: primary PID-controlled heating circuit + independent hardware-based thermal cutoff at 350 °C, compliant with IEC 61010-1 safety standards for laboratory equipment
• IP42-rated sealed enclosure protecting internal electronics from dust ingress and incidental liquid splashes—suitable for shared lab benches and multi-user environments
• Interchangeable round-bottom flask heater blocks (available separately) compatible with standard 50–1000 mL borosilicate glass flasks; optimized geometry ensures mechanical stability and thermal contact efficiency
• PTFE-coated stir bars in multiple diameters (5 × 20 mm, 8 × 30 mm, 10 × 40 mm) included as standard accessories, providing chemical resistance and consistent torque transmission across pH 1–14 and common solvents

Sample Compatibility & Compliance

The ES35A Pro accommodates vessels ranging from small test tubes (with optional adapter inserts) to 20 L jacketed reactors when used with external circulation systems. Its magnetic coupling strength supports stir bar retention in vessels up to 150 mm in diameter and liquids with dynamic viscosities up to 5,000 mPa·s at 25 °C. The device conforms to key international laboratory safety and performance benchmarks, including EN 61326-1 (EMC for laboratory equipment), EN 61010-1 (safety requirements), and ASTM E2935–22 (standard guide for validation of magnetic stirring systems). While not inherently 21 CFR Part 11 compliant, its analog control interface supports integration into validated workflows via external data loggers meeting ALCOA+ data integrity principles.

Software & Data Management

The ES35A Pro operates via intuitive front-panel controls with dual LED displays showing real-time speed (rpm) and plate temperature (°C). No embedded software or USB connectivity is provided—consistent with its design as a dedicated, low-maintenance utility instrument. For regulated environments requiring audit trails, users may pair the unit with third-party calibrated thermocouple probes and digital tachometers connected to validated data acquisition systems (e.g., LabVIEW-based platforms or ELN-integrated sensors). All operating parameters—including time-stamped start/stop events and maximum observed temperature—are manually recordable in lab notebooks per GLP Annex 11 guidance.

Applications

• Homogenization of reagent solutions prior to HPLC or ICP-MS analysis
• Controlled-temperature digestion of environmental samples (e.g., EPA Method 3050B acid leaching)
• Preparation of calibration standards under thermostatic conditions for UV-Vis spectrophotometry
• Accelerated solvent extraction (ASE) support heating for static extraction cells
• Synthesis reaction monitoring where gentle agitation prevents precipitate aggregation during crystallization
• Educational demonstrations of Arrhenius kinetics, phase transitions, and heat transfer phenomena

FAQ

Does the ES35A Pro support programmable ramp-and-soak temperature profiles?
No—this model features manual setpoint control only. For programmable thermal profiles, consider LabTech’s TC-series temperature controllers with external relay output compatibility.
Can it be used under inert atmosphere or vacuum conditions?
Yes, provided the vessel is appropriately sealed and the stir bar remains magnetically coupled; however, the unit itself is not rated for vacuum chamber integration.
What is the recommended maintenance interval for the magnetic drive assembly?
No scheduled maintenance is required; the permanent magnet system is solid-state and non-wearing. Wipe the heating surface with ethanol after each use and inspect stir bars for PTFE coating integrity every 6 months.
Is calibration documentation available for the built-in temperature and speed sensors?
Factory calibration certificates (traceable to NIST standards) are available upon request at time of purchase; field recalibration requires external reference instruments per ISO/IEC 17025 procedures.