VELP ROTAX6.8 Overhead Mixer

Overview

The VELP ROTAX6.8 Overhead Mixer is an engineered laboratory device designed for standardized agitation of solid–liquid suspensions under controlled rotational motion. It operates on the principle of overhead rocking (tilt-and-rotate) mixing, generating gentle yet reproducible mechanical energy to simulate natural leaching and solubilization processes in environmental and regulatory testing protocols. Unlike orbital shakers or vortex mixers, the ROTAX6.8 applies a defined angular displacement combined with low-speed rotation—optimized for compliance with DIN 38414 Part 2 (S2), the German standard for determining the elutriation behavior of solids in aqueous media. This method is widely adopted across EU-based environmental laboratories for assessing leachable fractions of contaminants—including heavy metals, organic pollutants, and soluble salts—from soils, sediments, sludges, and industrial waste matrices.

Key Features

• Overhead tilting mechanism with programmable 0–30 rpm rotation speed, ensuring consistent shear input without foaming or splashing.
• Dual-bottle configuration support: accommodates up to six 2 L wide-mouth glass or HDPE extraction bottles (e.g., DIN-compliant Schott Duran® type), or eight 1 L bottles—enabling parallel sample processing for statistical robustness.
• Adjustable bottle holder assembly with vertical travel range of 205–270 mm and maximum clamping diameter of 135 mm, compatible with standard DIN 38414-compliant containers.
• Integrated backlit LCD display providing real-time feedback on set speed, elapsed time, and operational status—no external controller required.
• Robust aluminum-alloy frame with vibration-dampening feet and IP20-rated electrical enclosure, suitable for continuous 24-hour operation in ISO 17025-accredited labs.
• Energy-efficient 100 W motor with thermal overload protection, meeting IEC 61000-3-2 harmonic current emission limits.

Sample Compatibility & Compliance

The ROTAX6.8 is validated for use with heterogeneous environmental samples including digested sludge, river sediment, landfill leachate precursors, and municipal solid waste residues. Its mechanical design ensures uniform suspension of particles ≥50 µm without attrition—critical when preserving particle integrity during leaching. The instrument fully supports DIN 38414-S2 methodology: 100 g dry-weight solid sample + 1 L deionized water in 2 L bottles, agitated for 24 h at 25 ± 2 °C. Post-filtration (0.45 µm membrane), eluates are analyzed per EN ISO 11885 (ICP-OES), EN ISO 17294-2 (ICP-MS), or EN ISO 15682 (TOC). It also aligns with supplementary frameworks including CEN/TS 14429 (characterization of waste) and EPA Method 1311 (TCLP), when adapted with appropriate bottle geometry and timing parameters.

Software & Data Management

While the ROTAX6.8 operates as a stand-alone analog-controlled unit, its operational parameters (speed, duration) are traceable via manual logbook entry or integration into lab-wide electronic lab notebook (ELN) systems. For GLP/GMP environments, users may pair it with time-stamped digital timers compliant with FDA 21 CFR Part 11 requirements (e.g., certified stopwatch modules with audit trail export). All mechanical settings are mechanically locked post-calibration; no firmware updates or cloud connectivity are implemented—minimizing cybersecurity exposure and validation burden in regulated QA/QC workflows.

Applications

• Leaching tests for contaminated soil screening prior to remediation planning.
• Validation of stabilization/solidification treatment efficacy in hazardous waste management.
• Preparation of representative aqueous extracts for ecotoxicity assays (e.g., Daphnia magna, algae growth inhibition).
• Method development for speciation analysis of arsenic, chromium(VI), or fluoride under near-neutral pH conditions.
• Interlaboratory comparison studies under EQA schemes coordinated by national reference laboratories (e.g., BfR, NAMUR).

FAQ

Does the ROTAX6.8 meet ISO/IEC 17025 calibration requirements?
Yes—its rotational speed is factory-calibrated using traceable tachometric reference standards (NIST-traceable optical encoder), with certificate of conformance supplied. Annual verification can be performed using handheld laser tachometers.
Can it be used for ASTM D5233 or EPA 1312 (SLM) protocols?
Not directly—the SLM protocol requires horizontal shaking at 30 ± 2 rpm with 30 mm amplitude; the ROTAX6.8 delivers tilting rotation, not linear oscillation. However, method adaptation is possible under §4.2 of ASTM D5233 for comparative leaching studies.
Is the unit suitable for acidic or alkaline extraction media?
Yes—provided bottles are chemically resistant (e.g., borosilicate glass or fluoropolymer-lined HDPE); the mixer’s structural components do not contact reagents.
What maintenance is required?
Biannual inspection of drive belt tension and bearing lubrication; cleaning of bottle clamps with ethanol; no scheduled motor servicing required within first 5 years of operation.
Does VELP provide IQ/OQ documentation?
Yes—upon request, VELP supplies customizable Installation Qualification (IQ) and Operational Qualification (OQ) templates aligned with Annex 15 and EU GMP guidelines, including test scripts for speed accuracy, load stability, and thermal drift verification.