Corning SS2I Single-Position Slow-Speed Magnetic Stirrer

Overview

The Corning SS2I Single-Position Slow-Speed Magnetic Stirrer is an engineered solution for precise, low-shear mixing of viscous, temperature-sensitive, or sediment-prone samples in laboratory and quality control environments. Designed around a closed-loop DC stepper motor architecture, the SS2I delivers exceptional speed stability and reproducibility across its operational range of 10–150 rpm—optimized specifically for applications where turbulent agitation must be avoided. Unlike conventional high-RPM stirrers, the SS2I employs a torque-controlled magnetic coupling system that maintains consistent rotational output regardless of load variation within its 2 L capacity limit. Its compact footprint (150 × 150 × 70 mm) and low-profile housing—constructed from UL-listed glass-filled resin—ensure compatibility with incubators, cold rooms, and laminar flow hoods while meeting stringent electrical safety requirements under both UL 61010-1 and EN 61010-1 (CE-marked). The device operates exclusively on 120 V / 60 Hz input power, making it suitable for standard North American laboratory infrastructure without external transformers or frequency converters.

Key Features

• Stable, digitally regulated speed control with ±2 rpm repeatability across the full 10–150 rpm range
• Single-position design with centered magnetic drive optimized for uniform field distribution over 150 mm diameter vessels
• Low-noise DC stepper motor providing consistent torque delivery and eliminating speed drift during extended operation
• Chemically resistant, non-porous glass-filled resin housing rated for continuous use at ambient temperatures up to 40 °C and relative humidity ≤80% (non-condensing)
• Integrated thermal protection circuitry preventing motor overheating during prolonged low-speed operation
• Compliance with UL 61010-1 and IEC/EN 61010-1 safety standards for laboratory electrical equipment
• Two-year limited warranty covering parts and labor under normal laboratory use conditions

Sample Compatibility & Compliance

The SS2I is validated for use with standard borosilicate glass bottles, polypropylene carboys, and stainless-steel containers up to 2 L volume and 150 mm maximum diameter. It supports common magnetic stir bars (e.g., PTFE-coated elliptical or cross-shaped designs) sized 30–50 mm in length. Due to its low-shear profile, the unit is frequently deployed in applications requiring adherence to ASTM D2196 (viscosity measurement of non-Newtonian fluids), USP (disintegration testing), and ISO 8503-2 (surface roughness assessment of coated substrates). While not inherently GLP/GMP-certified, the SS2I’s mechanical simplicity, absence of software-based controls, and deterministic performance make it suitable for inclusion in instrument qualification protocols (IQ/OQ) under FDA 21 CFR Part 11-compliant environments when paired with documented calibration procedures and maintenance logs.

Software & Data Management

The Corning SS2I is a stand-alone, analog-controlled instrument with no embedded firmware, touchscreen interface, or digital connectivity. Speed adjustment is performed via a calibrated rotary potentiometer with tactile detents at 10-rpm increments; no data logging, remote control, or audit trail functionality is provided. This design intentionally eliminates software validation burdens, reducing qualification overhead in regulated QC laboratories. Users maintain full traceability through manual entry into laboratory notebooks or electronic lab notebooks (ELNs), with speed settings recorded alongside batch identifiers, vessel geometry, and stir bar specifications. For laboratories requiring automated parameter tracking, integration with external programmable logic controllers (PLCs) or data acquisition systems is possible via optional analog voltage output modules (sold separately).

Applications

• Slow-rate dissolution testing of pharmaceutical tablets and capsules per USP
• Homogenization of high-viscosity polymer solutions prior to rheological characterization
• Gentle re-suspension of precipitated cell pellets in bioprocessing workflows
• Controlled mixing of catalyst slurries in heterogeneous reaction studies
• Preparation of calibration standards for ICP-MS and AAS analysis where particle settling must be minimized
• Long-duration stability studies involving temperature-cycled suspensions in environmental chambers

FAQ

Is the SS2I compatible with international voltage standards (e.g., 230 V / 50 Hz)?
No—the SS2I is configured exclusively for 120 V / 60 Hz input. Operation on other voltages requires an externally rated step-down transformer with sufficient VA rating and waveform fidelity to sustain stepper motor timing integrity.
Can the SS2I accommodate stir bars larger than 50 mm?
While physically possible, stir bars exceeding 50 mm may induce lateral wobble or inconsistent rotation due to magnetic field limitations at the drive plate perimeter; Corning recommends using stir bars between 30–45 mm for optimal coupling efficiency.
Does the unit include a stir bar?
No—stir bars are sold separately as consumables; Corning offers PTFE-coated elliptical stir bars (Cat. No. 440800 series) optimized for low-RPM applications.
What maintenance is required?
Routine cleaning of the top plate with isopropyl alcohol and periodic inspection of the magnetic drive surface for debris or scratches; no lubrication or internal servicing is required under normal operating conditions.
Is calibration documentation available?
Corning provides a Certificate of Conformance with each unit; NIST-traceable speed calibration services are available through authorized third-party metrology providers upon request.