Mary Ann® SS-25 Rotary Laboratory Sifter

Overview

The Mary Ann® SS-25 Rotary Laboratory Sifter is a precision-engineered, gravity-fed dry particle sizing instrument designed for reproducible sieve analysis in quality control, R&D, and regulatory-compliant testing environments. Based on the standardized rotary-tap principle defined in ASTM E11, ISO 3310-1, and USP <786>, the SS-25 employs a synchronized 45° tilt and rotational motion combined with controlled mechanical tapping to induce efficient stratification and passage of particles through stacked test sieves. Its robust cast-aluminum housing—finished with durable hardwood veneer—and fully enclosed cabinet structure ensure operator safety, dust containment, and long-term mechanical stability. The unit accommodates standard ASTM/ISO-compliant test sieves with diameters of 203 mm (8 in) or 305 mm (12 in), supporting stack heights up to 660 mm (26 in) without clamping mechanisms—a design feature that accelerates setup while maintaining alignment integrity across all sieve levels.

Key Features

• Clamp-free sieve stacking system enabling rapid assembly of up to 10 × 203 mm or 6 × 305 mm sieves in full-height configuration (660 mm)
• Precise digital timer with ±1-second accuracy and programmable range from 1 second to 99 minutes
• Integrated support frame doubles as both structural base and dedicated sieve storage rack
• Reversible cabinet door installation (left- or right-hinged) for flexible laboratory layout integration
• Dual-voltage compatibility: SS-25 (115 V / 60 Hz) and SS-25F (220 V / 50 Hz) variants available for global deployment
• Rotary-tap motion profile engineered to emulate manual sieving protocols while delivering superior repeatability and inter-laboratory comparability

Sample Compatibility & Compliance

The SS-25 is validated for use with free-flowing, non-cohesive dry powders and granules across a nominal particle size range of 4.75 mm (No. 4 sieve) down to 20 µm (No. 635 sieve). It supports all standard test sieve frames manufactured per ASTM E11 and ISO 3310-1 specifications—including stainless steel, brass, and nylon mesh variants—with openings ranging from 20 µm to 4.75 mm. The device meets mechanical performance criteria outlined in ISO/IEC 17025-accredited laboratories for sieve analysis validation. When operated with documented calibration procedures and traceable reference standards, data generated by the SS-25 satisfies requirements for GLP and GMP documentation, including audit-trail readiness for FDA 21 CFR Part 11–governed environments where electronic records are maintained.

Software & Data Management

While the SS-25 operates as a standalone electromechanical instrument without embedded firmware or proprietary software, its deterministic timing control and repeatable motion profile enable seamless integration into LIMS and ELN workflows. Users may pair the sifter with external digital logging systems (e.g., USB-connected timers, PLC-based process controllers, or industrial IoT gateways) to capture start/stop timestamps, cycle counts, and operator IDs. All mechanical parameters—including tilt angle, rotation speed (fixed at 275 rpm), tap frequency (150 taps/min), and dwell time—are factory-set and mechanically locked to eliminate user-induced variability. Calibration verification reports and maintenance logs can be maintained manually or imported into compliant document management systems supporting version control and electronic signatures.

Applications

• Pharmaceutical excipient and active ingredient particle size distribution (PSD) verification per USP <786> and EP 2.9.32
• Quality assurance of catalysts, pigments, ceramics, and metal powders in advanced manufacturing
• Aggregate gradation analysis in construction materials testing labs
• Food powder consistency screening (e.g., flour, sugar, dairy blends) under Codex Alimentarius guidelines
• Educational demonstration of sieve analysis fundamentals in materials science curricula
• Method transfer and inter-laboratory comparison studies requiring high inter-operator reproducibility

FAQ

What sieve diameters does the SS-25 accommodate?
The SS-25 accepts standard test sieves with either 203 mm (8 in) or 305 mm (12 in) frame diameters.
Is the SS-25 compliant with ASTM and ISO standards?
Yes—the instrument’s motion profile, dimensional tolerances, and operational methodology conform to ASTM E11 and ISO 3310-1 for mechanical sieve shakers.
Does the SS-25 require external clamping for multi-sieve stacks?
No—its self-aligning stack design eliminates the need for clamps, even at maximum height (660 mm).
Can the SS-25 be used for wet sieving?
No—it is strictly intended for dry sieve analysis; liquid exposure may compromise bearing integrity and electrical safety.
What is the typical service life and maintenance schedule?
With routine cleaning and annual inspection of drive belts, bearings, and tap mechanism lubrication, the SS-25 achieves >15 years of continuous laboratory service under normal QC workloads.