OHAUS GUARDIAN™5000 Heated Magnetic Stirrer

Overview

The OHAUS GUARDIAN™5000 Heated Magnetic Stirrer is an engineered platform for precise thermal and mechanical control of liquid samples in research laboratories, academic teaching facilities, and industrial quality control environments. It operates on the principle of contactless magnetic coupling—where a rotating permanent magnet (SmCo) beneath the heating plate induces rotation of a stir bar immersed in the sample—combined with resistive ceramic heating for uniform thermal delivery. Designed to meet the operational rigor of GLP-compliant workflows, the system supports temperature-sensitive protocols including buffer preparation, media sterilization, pH equilibration, enzymatic denaturation studies, and exothermic/endothermic reaction monitoring. Its dual-function architecture integrates high-fidelity thermal regulation (±1 °C accuracy below 100 °C at the plate surface; ±0.5 °C with optional Pt100/Pt1000 probe) with robust mechanical agitation across a wide dynamic range (50–1800 rpm), enabling reproducible mixing of low- to medium-viscosity solutions up to 20 L in compatible vessels.

Key Features

• Triple-mode temperature control: rapid ramp, precision hold, and overshoot-suppressed stabilization—optimized for both kinetic heating and steady-state thermal maintenance
• Ceramic square heating plate (18 cm × 18 cm) offering superior thermal uniformity, chemical resistance, and long-term stability versus conventional aluminum or coated variants
• High-energy samarium-cobalt (SmCo) drive magnet ensuring consistent torque transmission even under viscous loads or off-center vessel placement
• IP32-rated enclosure with fully metallic chassis, smooth non-porous surfaces, and front-panel tilt angle (≥15°) for ergonomic visual monitoring from bench height
• Integrated audible alarm and dual-status LED indicators: green for active heating/stirring, amber for >150 °C warning—supporting lab safety protocols per ISO 13857 and IEC 61010-1
• RS232 serial interface compliant with standard SCPI command sets, enabling integration into automated data logging systems or centralized lab instrument networks

Sample Compatibility & Compliance

The GUARDIAN™5000 accommodates standard laboratory glassware—including beakers, Erlenmeyer flasks, and jacketed reactors—up to 20 L volume when used with appropriately sized stir bars (e.g., 40–80 mm elliptical or cross-shaped). Compatibility extends to aqueous, organic, and mildly corrosive solvents; however, prolonged exposure to hydrofluoric acid or molten alkali metals is not recommended. The device complies with CE marking requirements under the EU Low Voltage Directive (2014/35/EU) and Electromagnetic Compatibility Directive (2014/30/EU), and carries TÜV certification per EN 61010-1:2010 for electrical safety in laboratory equipment. Temperature calibration routines support traceable verification at three user-defined setpoints (e.g., 25 °C, 100 °C, 300 °C), aligning with internal quality procedures required under ISO/IEC 17025 and FDA 21 CFR Part 11 when paired with validated software.

Software & Data Management

While the unit operates autonomously via its front-panel interface, the RS232 port enables bidirectional communication with external PCs or PLCs. Supported commands include real-time readout of actual temperature (plate or probe), setpoint adjustment, speed modulation, timer activation, and status polling. When integrated with OHAUS-provided or third-party compliant software (e.g., LabVIEW-compatible drivers or custom Python scripts using pySerial), full audit trails—including timestamps, operator IDs, parameter changes, and alarm events—can be generated for regulatory documentation. All firmware updates are delivered via secure USB-to-serial bridges and undergo cryptographic signature validation prior to installation.

Applications

• Preparation of microbiological growth media requiring precise thermal dissolution and homogenization
• Controlled thermal cycling during polymer dissolution or nanoparticle dispersion protocols
• Standardized buffer titration workflows where pH drift must be minimized through constant mixing during temperature ramping
• Accelerated stability testing of pharmaceutical formulations under defined thermal stress conditions
• Teaching labs conducting calorimetry fundamentals, Arrhenius kinetics, or viscosity-temperature correlation experiments
• QC release testing of raw materials where batch-to-batch consistency in dissolution rate is critical

FAQ

What temperature probe options are supported?
The GUARDIAN™5000 accepts industry-standard Pt100 and Pt1000 RTD probes; both require separate purchase and connection via the rear-panel analog input terminal.
Is the heating plate interchangeable between models?
No—the ceramic square plate is mechanically and thermally integrated into the e-G52HS07C variant; other GUARDIAN™5000 configurations (e.g., round aluminum-coated plates) are not field-swappable.
Can the unit operate continuously for extended periods?
Yes—designed for unattended operation up to 99 hours 59 minutes; thermal cut-off and stall detection prevent overheating or motor damage during prolonged use.
Does it support GLP-compliant electronic recordkeeping?
When connected to validated external software with audit-trail functionality and user access controls, the RS232 output meets core data integrity requirements outlined in ALCOA+ principles.
What is the minimum ambient temperature for safe operation?
The device is rated for continuous operation between 5 °C and 40 °C ambient, with relative humidity ≤80% non-condensing—consistent with typical Class II laboratory environmental specifications.