Gilson Silent Sifter® SS-21

Overview

The Gilson Silent Sifter® SS-21 is a precision-engineered, low-noise mechanical sieve shaker designed for standardized particle size distribution analysis in compliance with ASTM E11, ISO 3310-1, and USP <786>. Unlike conventional rotary or vibratory sieves, the SS-21 employs a patented dual-roller rotational–tapping mechanism that simultaneously rotates the sieve stack while delivering controlled vertical impacts—mimicking manual sieving kinetics while ensuring high reproducibility across operators and laboratories. Its core architecture integrates acoustic damping via optimized structural mass distribution, vibration-isolating drive train components, and an acoustically sealed cabinet constructed from dense MDF with powder-coated ASTM A513 steel framing. This design achieves a certified 7–10 dB(A) reduction in operational noise relative to legacy rotary sifters—directly supporting OSHA 29 CFR 1910.95 hearing conservation requirements without compromising analytical fidelity or throughput.

Key Features

• Acoustically optimized cabinet with gasketed, lever-latched door for dust containment and enhanced noise attenuation
• Dual rubber-covered stainless-steel drive rollers enabling smooth, non-slip rotation of stacked sieves (up to 20 × 8″ half-height or 6 × 12″ full-height)
• Integrated tapping action synchronized with rotation—mechanically replicating hand-sieving dynamics per ASTM D6913 and ISO 13320
• High-visibility 0.5-inch (12.7 mm) LED digital timer with ±1-second accuracy, programmable up to 99 minutes; includes pause/resume functionality and audible 5-second completion alert
• Robust ¼ HP continuous-duty motor rated for sustained operation under load; thermally protected and compliant with UL/CSA safety standards
• Ergonomic rotary knob for intuitive cabinet repositioning—no clamps or tools required for setup or maintenance
• UHMW polyethylene-tipped 6061 aluminum hammer assembly for consistent impact energy and wear resistance
• Locking swivel casters (included) for safe, stable mobility and secure floor anchoring during operation

Sample Compatibility & Compliance

The SS-21 accommodates standard ASTM E11 and ISO 3310-1 test sieves in diameters of 200 mm (8″) and 300 mm (12″), with full-height, half-height, and intermediate-height configurations. It supports sieve mesh ranges from No. 1 (25.0 mm) to No. 635 (20 µm), covering coarse aggregates, fine powders, pharmaceutical excipients, catalysts, and mineral fines. The enclosed cabinet design limits airborne particulate dispersion—critical for handling respirable crystalline silica (RCS), quartz, or other OSHA-regulated aerosols. All electrical components meet IEC 61000-6-3 EMC standards and are CE-marked for use in EU-based GLP-compliant laboratories. Device firmware supports audit-ready operation logs when paired with optional SSA-76 controller upgrades compliant with FDA 21 CFR Part 11 electronic record requirements.

Software & Data Management

While the SS-21 operates as a standalone electromechanical instrument, its timing and cycle control architecture is compatible with external data acquisition systems via analog trigger output (TTL-compatible). When integrated with Gilson’s optional SSA-76 Digital Timer/Controller, users gain timestamped run records—including start time, duration, pause events, and completion alerts—stored in non-volatile memory. These logs support traceability in regulated environments governed by ISO/IEC 17025, USP <429>, or GMP Annex 11. Firmware updates (via USB interface on SSA-76 units) maintain alignment with evolving regulatory expectations for equipment qualification and periodic verification.

Applications

• Aggregate gradation testing per ASTM C136/C136M and AASHTO T 27
• Pharmaceutical granule and API particle sizing per USP <786> and EP 2.9.32
• Soil and sediment analysis per ASTM D6913 and ISO 14688-1
• Cement and fly ash fineness determination per ASTM C786 and EN 196-6
• Quality control of metal powders in additive manufacturing feedstock screening
• Environmental sample processing for PM10/PM2.5 fractionation studies

FAQ

What voltage configurations are available for the SS-21?

The SS-21 operates at 115 V / 60 Hz (4.7 A); the SS-21F variant is configured for 230 V / 50 Hz (5.4 A). Both models share identical mechanical specifications and acoustic performance.
Can the SS-21 accommodate ISO-standard 300 mm sieves?

Yes—the SS-21 accepts both 200 mm (8″) and 300 mm (12″) diameter sieves, including full-height, half-height, and intermediate-height frames per ISO 3310-1.
Is the SS-21 compliant with OSHA hearing conservation standards?

Yes—its certified 7–10 dB(A) noise reduction enables extended daily operation below the 85 dB(A) 8-hour TWA threshold, reducing reliance on PPE and supporting engineering controls per OSHA 29 CFR 1910.95.
Does the unit include a sieve stack or are sieves sold separately?

Sieves are not included; the SS-21 is supplied with a floor stand, locking casters, and controller. ASTM and ISO test sieves must be ordered separately based on application-specific mesh requirements.
How is calibration and verification performed?

Time accuracy is verified using a Class 1 stopwatch traceable to NIST; mechanical performance (rotation speed, tap frequency, amplitude) is validated annually per Gilson’s Recommended Verification Protocol (RVP-SS21), which aligns with ISO/IEC 17025 clause 6.5.2.