IKA RW20 Digital Overhead Stirrer
| Brand | IKA |
|---|---|
| Origin | Germany |
| Model | RW 20 Digital |
| Max. Mixing Volume | 20 L |
| Speed Range | 60–2000 rpm (two ranges: 60–500 rpm / 240–2000 rpm) |
| Viscosity Range | up to 10,000 mPa·s |
| Motor Input/Output Power | 70 W / 35 W |
| Shaft Output Power | 26 W |
| Duty Cycle | 100% |
| Chuck Torque at 100 rpm | 150 N·cm |
| Chuck Capacity | 0.5–10 mm |
| Support Rod Diameter/Length | 13 mm / 160 mm |
| Dimensions (W×D×H) | 88 × 212 × 294 mm |
| Weight | 3.1 kg |
| Protection Class | IP20 (DIN EN 60529) |
Overview
The IKA RW 20 Digital is a high-performance overhead mechanical stirrer engineered for precision mixing and dispersion tasks in research laboratories, quality control environments, and small-scale production settings. Utilizing a robust brush-type DC motor with dual-speed electronic control, the RW 20 delivers consistent torque across its full operational range—enabling reliable handling of low- to medium-viscosity fluids (up to 10,000 mPa·s) without thermal overload or speed drift. Its 100% duty cycle rating ensures uninterrupted operation during extended batch processing, while the integrated digital display provides real-time, high-resolution speed readout (±1 rpm resolution) for traceable process documentation. Designed according to DIN EN 60529 standards, the unit features an IP20-rated enclosure suitable for dry, non-corrosive laboratory environments—making it compatible with standard fume hoods and benchtop installations where dust ingress is not a primary concern.
Key Features
- Dual-range speed control: Low range (60–500 rpm) optimized for viscous media and gentle homogenization; high range (240–2000 rpm) for rapid dispersion and emulsification
- Digital LED speed display with ±1 rpm accuracy and memory retention after power cycling
- High-torque chuck (150 N·cm at 100 rpm) with self-centering collet mechanism accommodating shaft diameters from 0.5 to 10 mm
- Modular support system: 13 mm diameter, 160 mm length support rod with adjustable clamping bracket (R 1826) for secure vertical alignment
- Compact footprint (88 × 212 × 294 mm) and lightweight design (3.1 kg) facilitating easy integration into multi-instrument workstations
- Brush-type DC motor delivering 26 W shaft output power—engineered for thermal stability and long-term reproducibility under continuous load
Sample Compatibility & Compliance
The RW 20 Digital supports a wide range of sample containers—including glass beakers (500 mL to 20 L), stainless steel reactors, and jacketed vessels—when paired with appropriate impellers (e.g., R1342 propeller, anchor, or paddle types). It complies with CE marking requirements and conforms to DIN EN 61000-6-3 (EMC emission) and DIN EN 61000-6-2 (EMC immunity) standards. While not intrinsically rated for hazardous area use, its IP20 protection level meets general-purpose laboratory safety guidelines per DIN EN 60529. For regulated environments requiring audit trails, the device supports manual logging protocols aligned with GLP and ISO/IEC 17025 documentation practices; however, it does not include built-in FDA 21 CFR Part 11-compliant electronic signature or data archiving functionality.
Software & Data Management
The RW 20 Digital operates as a standalone instrument without proprietary software dependency. All operational parameters—including set speed, actual speed, and runtime—are accessible via front-panel controls and the integrated LED display. No USB, RS-232, or Ethernet interface is provided; therefore, external data acquisition requires analog tachometer coupling or third-party optical sensing solutions. For laboratories implementing LIMS or ELN systems, manual entry of speed settings and duration remains the standard workflow. The absence of firmware-upgradable logic ensures long-term calibration stability and eliminates version-control complications often associated with connected instrumentation.
Applications
- Homogenization of aqueous and organic-phase solutions in pharmaceutical formulation development
- Preparation of polymer dispersions and colloidal suspensions for materials science characterization
- Mixing of culture media and buffer solutions in microbiology and cell biology workflows
- Blending of adhesives, coatings, and cosmetic emulsions during R&D prototyping
- Stirring of reaction mixtures in synthetic chemistry under ambient temperature conditions
- Supporting ASTM D1893 (viscosity measurement of asphalt binders) and ISO 3219 (rotational viscometry) sample conditioning steps
FAQ
What is the maximum viscosity this stirrer can handle?
The RW 20 Digital is rated for fluids up to 10,000 mPa·s when operated within its low-speed range (60–500 rpm) using appropriately sized impellers.
Is the unit compatible with temperature-controlled reactors?
Yes—provided the reactor vessel allows vertical shaft insertion and the external heating/cooling system does not exceed the support rod’s thermal tolerance (standard aluminum alloy construction; no active cooling interface).
Does the RW 20 Digital support remote start/stop or analog speed control?
No—it lacks 0–10 V or 4–20 mA input/output terminals and does not support external triggering signals.
Can the display show torque or power consumption in real time?
No—the display shows only rotational speed; torque and power values are fixed by motor design and not dynamically measured or reported.
What impeller types are recommended for 20 L mixing volumes?
For optimal radial flow and top-to-bottom circulation in 20 L vessels, IKA recommends the R1342 three-blade propeller (included in the RW 20 Digital 20 L kit) or custom-fabricated anchor impellers with 80–90% vessel diameter clearance.
