WIGGENS WOHS-15 Pro Overhead Stirrer

Overview

The WIGGENS WOHS-15 Pro Overhead Stirrer is an engineered solution for high-precision, high-torque mixing and dispersion tasks in research laboratories, quality control environments, and pilot-scale process development. Designed around a brushless DC motor architecture, it delivers consistent rotational performance across its full speed range—from gentle homogenization at 50 rpm to high-shear dispersion at 15,000 rpm—without thermal degradation or commutation wear. Its overhead configuration eliminates shaft flex and torque loss associated with magnetic stirrers, enabling reproducible agitation of viscous, heterogeneous, or temperature-sensitive media. The device operates on the principle of direct mechanical coupling between motor and impeller via a rigid hollow shaft, ensuring minimal energy dissipation and precise torque transmission. This architecture supports ISO 8573-compliant cleanroom-compatible operation when paired with appropriate drive shafts and impellers, and meets mechanical safety requirements per IEC 61010-1 for laboratory equipment.

Key Features

• Brushless DC motor delivering 29 N·cm nominal torque with thermal stability and extended service life—no carbon brushes to replace or arcing risks.
• Self-locking, tool-free chuck system accommodating stirring elements from 0.5 mm to 10 mm diameter; hollow shaft (10.2 mm inner diameter) allows integration with temperature probes or pH electrodes during active mixing.
• TFT display with real-time feedback of speed, direction, elapsed time, and optional temperature (when used with compatible Pt100 or thermocouple sensors).
• Bi-directional rotation control (clockwise/counterclockwise) for optimized suspension of particulates or prevention of vortex-induced splashing in low-surface-tension systems.
• Precise speed regulation with ≤1 rpm resolution and ±3% accuracy above 300 rpm—validated per ASTM E29-23 rounding conventions for instrument calibration reporting.
• Dual-mode input: tactile rotary encoder + capacitive touch keys for intuitive parameter entry under gloved-hand conditions.
• Programmable timer (00:00:01–99:59:59) supporting unattended operation with automatic shutdown and audible/visual alarm triggers.

Sample Compatibility & Compliance

The WOHS-15 Pro accommodates a broad range of sample types—including aqueous suspensions, polymer melts, emulsions, ceramic slurries, and pharmaceutical suspensions—up to 15 L volume (in water-equivalent viscosity). Its torque output enables stable agitation of media up to 20,000 mPa·s without stalling, making it suitable for applications governed by USP (Viscosity) and ASTM D2196 (Rheological Properties of Non-Newtonian Materials). The unit complies with CE marking requirements (2014/30/EU EMC Directive and 2014/35/EU Low Voltage Directive), and its electrical isolation meets IEC 61010-1:2010 safety standards for measurement, control, and laboratory use. When integrated into GxP workflows, audit-trail-capable software (via optional RS232/USB interface) supports 21 CFR Part 11 compliance for electronic records and signatures.

Software & Data Management

While the WOHS-15 Pro operates as a standalone instrument, its optional communication interface (RS232 or USB) enables bidirectional data exchange with third-party LIMS or ELN platforms. Firmware supports SCPI-like command syntax for remote speed, direction, timer, and status interrogation. Logged operational parameters—including timestamped speed profiles, torque estimates (derived from current draw), and thermal events—are exportable in CSV format for traceability. The embedded firmware architecture includes non-volatile memory retention for user-defined presets (up to 10 protocols), each configurable with ramp profiles, hold durations, and endpoint actions—supporting GLP-aligned experimental repeatability.

Applications

• Preparation of homogeneous catalyst slurries in fine chemical synthesis.
• Dispersion of nanomaterials (e.g., graphene oxide, TiO₂ nanoparticles) in solvent-based matrices under inert atmosphere gloveboxes.
• Accelerated stability testing of topical formulations per ICH Q5C guidelines, where shear history directly impacts phase separation kinetics.
• Batch-wise dissolution testing of modified-release tablets in USP Apparatus II (paddle) configurations using custom adapter mounts.
• In-process mixing of high-viscosity adhesives and sealants prior to rheological characterization on rotational rheometers.

FAQ

Can the WOHS-15 Pro be used in explosion-proof environments?

No—this model lacks ATEX or IECEx certification. For hazardous area use, consult WIGGENS’ intrinsically safe overhead stirrer variants (e.g., WOHS-EX series) with certified barrier interfaces.
Is the temperature measurement function built-in or requires external hardware?

Temperature sensing is optional and requires connection of a calibrated Pt100 probe or K-type thermocouple via the auxiliary port; no internal sensor is included.
What impeller geometries are recommended for high-viscosity mixing?

Anchor, helical ribbon, or double-helical impellers mounted on rigid shafts are advised for viscosities >5,000 mPa·s; maximum tip speed should remain below 12 m/s to avoid cavitation or excessive heat generation.
Does the unit support analog signal output for PLC integration?

Not natively—the WOHS-15 Pro provides digital serial communication only. Analog 0–10 V or 4–20 mA outputs require external signal converters compliant with IEC 61000-6-2 immunity standards.
How often does the motor require maintenance?

The brushless DC motor is maintenance-free over its rated service life (≥20,000 hours at 70% load); only periodic inspection of chuck integrity and shaft concentricity is recommended per ISO 5389:2018.