IKA RW 20 digital Overhead Stirrer

Overview

The IKA RW 20 digital is a high-performance overhead stirrer engineered for precision, reliability, and ergonomic operation in routine laboratory environments. Based on the proven RW 20 platform—among IKA’s most widely deployed mechanical stirring systems—the digital variant integrates a fully integrated speed display, refined motor control architecture, and enhanced thermal management to support continuous-duty operation at full load. It operates on the principle of direct-drive rotational torque transmission via a keyed shaft and interchangeable chuck system, delivering consistent shear input across diverse fluid matrices—from low-viscosity aqueous solutions to highly structured non-Newtonian suspensions up to 10,000 mPa·s. Designed for benchtop integration in QC labs, R&D facilities, and pilot-scale formulation workflows, the RW 20 digital meets the mechanical robustness and repeatability requirements of ISO/IEC 17025-accredited testing environments when operated within defined parameter boundaries.

Key Features

• Full-digit LED speed display with real-time rpm feedback, eliminating analog scale interpretation errors
• Dual-range speed control: Low range (60–500 rpm) optimized for high-torque, low-shear mixing; High range (240–2000 rpm) for rapid dispersion and homogenization
• Continuous 100% duty cycle rating enabled by thermally stabilized 35 W output motor and passive aluminum housing heat dissipation
• Ergonomic vertical form factor (294 mm height) minimizes benchtop footprint while maximizing clearance beneath fume hoods or reactor vessels
• Self-centering keyless chuck (0.5–10 mm capacity) with 150 N·cm maximum torque at 100 rpm ensures secure retention of standard ISO 8687–compliant impellers and anchor blades
• Integrated support rod (Ø13 mm × 160 mm) compatible with standard IKA clamping systems and third-party universal stands meeting DIN 12877 specifications

Sample Compatibility & Compliance

The RW 20 digital accommodates a broad spectrum of sample types—including aqueous buffers, polymer solutions, ceramic slurries, pharmaceutical suspensions, and food emulsions—within its validated operational envelope of up to 20 L water-equivalent volume and 10,000 mPa·s viscosity. Its IP20 ingress protection rating (per DIN EN 60529) confirms suitability for dry, non-condensing indoor laboratory environments but excludes use in wet-process or splash-prone settings without supplemental shielding. While not intrinsically certified for hazardous area operation, the unit complies with EU Machinery Directive 2006/42/EC and Low Voltage Directive 2014/35/EU. For GLP/GMP-regulated workflows, audit-ready operation requires documented calibration of speed accuracy (±2% full scale per IKA calibration certificate option) and traceable maintenance logs per ISO/IEC 17025 clause 6.4.3.

Software & Data Management

The RW 20 digital is a standalone analog-digital hybrid instrument with no embedded microcontroller or software interface. Speed selection and monitoring occur exclusively via front-panel rotary encoder and LED display; no USB, RS-232, or Ethernet connectivity is provided. Consequently, it does not generate electronic records, lacks audit trail capability, and is not compliant with FDA 21 CFR Part 11 for electronic signatures or data integrity requirements. For laboratories requiring electronic data capture, integration with external tachometric sensors or programmable logic controllers (PLCs) is feasible via optional analog 0–10 V speed feedback output (available on select configurations). All firmware-free operation simplifies IQ/OQ validation protocols and reduces cybersecurity surface area in regulated infrastructure.

Applications

• Batch preparation of culture media and buffer solutions in microbiology and cell biology labs
• Dispersion of nanomaterials (e.g., graphene oxide, TiO₂ nanoparticles) in solvent-based carriers under controlled shear history
• Viscosity profiling of adhesives, coatings, and personal care formulations during stability testing
• Mixing of high-density catalyst slurries in fine chemical synthesis development
• Standardized dissolution testing per USP using paddle or basket assemblies mounted via IKA-compatible adapters
• Homogenization of vaccine adjuvant suspensions prior to fill-finish process qualification

FAQ

Is the RW 20 digital suitable for use with corrosive solvents such as concentrated acids or halogenated hydrocarbons?
The standard stainless-steel shaft and aluminum housing are not chemically resistant to aggressive oxidizers or halogenated solvents. For such applications, IKA recommends the RW 20 digital with optional PTFE-coated shaft and chemically inert chuck components (Order Code: RW 20 digital-CHEM).
Can the unit maintain constant torque across its entire speed range?
No. The RW 20 digital delivers rated torque only within specified speed bands: maximum 150 N·cm is achievable at ≤100 rpm; torque decreases inversely with increasing speed due to fixed-power motor characteristics.
Does IKA provide NIST-traceable calibration documentation?
Yes—upon request, IKA issues a factory calibration certificate (traceable to PTB, Germany) verifying speed accuracy at three points (100, 1000, and 2000 rpm) against primary standards, valid for 12 months from date of issue.
What impeller types are recommended for high-viscosity mixing?
Anchor, helical ribbon, and double-helix impellers with diameters ≥⅔ vessel ID are preferred for viscosities >5,000 mPa·s; all must be dynamically balanced and secured with M6 locking screws compatible with the 0.5–10 mm chuck range.
Is the support rod compatible with third-party lab stands?
Yes—the Ø13 mm diameter and standardized metric threading conform to DIN 12877 Type A mounting interfaces, enabling interoperability with stands from Fisher Scientific, VWR, and other ISO-compliant manufacturers.