Myingpu S312-250 Constant-Speed Stirrer

Overview

The Myingpu S312-250 Constant-Speed Stirrer is a robust, benchtop-mounted mechanical stirrer engineered for reproducible mixing and dispersion of low- to medium-viscosity liquids in laboratory and pilot-scale environments. It operates on the principle of direct-coupled rotational agitation via an AC induction motor, delivering consistent torque across its full speed range without electronic feedback-based closed-loop regulation—hence classified as a *constant-speed* (not variable-speed or programmable) stirrer. Unlike digitally controlled systems, the S312-250 relies on analog frequency conversion to maintain stable output under varying load conditions, making it particularly suitable for applications where steady-state homogenization—not dynamic ramping or endpoint control—is the primary requirement. Its mechanical architecture prioritizes durability and operational simplicity, with minimal electronics exposed to potential chemical vapor or splash ingress.

Key Features

• 250 W AC induction motor with high thermal tolerance and continuous-duty rating, optimized for sustained operation at elevated speeds
• Frequency-conversion-based speed regulation ensures minimal speed drift (< ±3% full scale) across the 60–1400 rpm range, even when stirring viscous or dense suspensions
• LED digital RPM display provides real-time, non-contact readout with 1 rpm resolution, eliminating parallax error associated with analog dials
• Heavy-duty stainless steel support rod (800 mm height) and dual-clamp vertical assembly accommodate both overhead stirrers and auxiliary fixtures such as pH electrodes or temperature probes
• Universal chuck accepts standard stirring rods from Φ1.5 mm to Φ13 mm diameter, compatible with glass, PTFE-coated, and stainless-steel shafts up to 450 mm in length
• No integrated heating or cooling elements—designed exclusively for mechanical agitation; may be used in conjunction with external water baths or jacketed vessels

Sample Compatibility & Compliance

The S312-250 is validated for use with aqueous solutions, organic solvents, polymer emulsions, colloidal suspensions, and low-yield-stress slurries—provided viscosity remains below ~5,000 mPa·s at operating temperature. It is not recommended for highly abrasive particulates (>100 µm median size), thixotropic gels, or shear-sensitive biopolymers requiring precise shear-rate profiling. While the unit itself carries no CE, UL, or IEC certification, its electrical design conforms to GB/T 22794–2008 (Chinese national standard for laboratory stirrers), and its mechanical construction aligns with ISO 8573-1:2010 general safety principles for rotating equipment. Users deploying this stirrer in regulated environments (e.g., pharmaceutical QC labs) must validate performance per internal SOPs and document calibration traceability to NIST-traceable tachometers.

Software & Data Management

The S312-250 is a standalone hardware device with no embedded firmware, USB interface, or data logging capability. All operational parameters—including setpoint speed and runtime—are manually configured and monitored via front-panel controls and LED display. Consequently, it does not support FDA 21 CFR Part 11-compliant audit trails, electronic signatures, or automated report generation. For laboratories requiring electronic recordkeeping, integration with external data acquisition systems (e.g., via TTL pulse output from optional tachometer sensors) is possible but requires third-party configuration and validation. Routine maintenance logs and usage records must be maintained manually per GLP/GMP documentation standards.

Applications

• Preparation of buffer solutions, culture media, and reagent blends in microbiology and molecular biology labs
• Homogenization of catalyst slurries and precursor mixtures in fine chemical synthesis
• Blending of excipients and active pharmaceutical ingredients (APIs) during pre-formulation studies
• Standardized mixing protocols in ASTM D1209 (color measurement) and ISO 787-11 (dispersion stability testing)
• Classroom demonstrations of fluid dynamics, Newtonian behavior, and mass transfer kinetics
• Batch conditioning of wastewater samples prior to COD, BOD, or turbidity analysis

FAQ

Does the S312-250 support programmable speed ramps or timed operation?
No. It is a manually operated constant-speed stirrer with analog speed selection only.
Can it be used with corrosive solvents such as concentrated HCl or NaOH solutions?
Yes—provided all wetted parts (stir bar, clamp, and rod) are chemically compatible; the base housing is not solvent-sealed and should be protected from splashes.
Is the motor thermally protected against overload?
Yes. The AC induction motor includes built-in thermal cut-off circuitry that interrupts power if winding temperature exceeds safe operating limits.
What is the maximum vessel diameter supported by the standard clamp assembly?
The vertical support rod allows clearance for vessels up to 300 mm in outer diameter when using a standard 450 mm stir rod.
Does Myingpu provide calibration certificates or metrological traceability documentation?
No factory-issued calibration certificate is included; users must perform periodic verification using an external handheld tachometer calibrated to ISO/IEC 17025-accredited standards.