IKA RW 28 digital High-Performance Mechanical Stirrer

Overview

The IKA RW 28 digital is a high-torque, microprocessor-controlled mechanical stirrer engineered for reproducible mixing of medium-to-high viscosity samples in laboratory and pilot-scale environments. Utilizing a robust brushless DC motor coupled with a dual-range planetary gear transmission, it delivers precise rotational control across two distinct speed bands—optimized for both high-torque low-speed operation (60–400 rpm) and high-speed dispersion (240–1400 rpm, depending on line frequency). Its design adheres to fundamental principles of fluid dynamics in viscous regimes, where torque delivery—not just rotational speed—is critical for achieving homogeneous suspension, emulsification, or dissolution. With a maximum rated torque of 900 N·cm at 60 rpm and an overload capacity of 1144 N·cm, the RW 28 digital maintains consistent power transfer even under demanding load conditions, such as stirring polymer solutions, ceramic slurries, or pharmaceutical pastes. The unit operates continuously at 100% duty cycle and incorporates integrated thermal protection that automatically limits motor temperature rise—ensuring long-term reliability without manual intervention.

Key Features

• Two selectable speed ranges (Range I: 60–400 rpm; Range II: 240–1400 rpm) for optimized performance across viscosity gradients
• Digital LED speed display with ±1 rpm setting accuracy and real-time feedback
• Hollow stainless-steel shaft (10.5 mm inner diameter) enabling insertion of temperature probes, pH electrodes, or auxiliary sensors during operation
• Integrated overload protection with error-code display for immediate fault identification
• Ergonomic cast-aluminum housing with thermoplastic polymer coating for chemical resistance and mechanical durability
• Low-noise operation at 62.5 dB(A) under no-load conditions—suitable for shared lab environments
• IP40-rated enclosure providing protection against solid objects ≥1 mm; compliant with DIN EN 60529
• Universal voltage compatibility (100–240 V, 50/60 Hz) supporting global deployment without external transformers

Sample Compatibility & Compliance

The RW 28 digital accommodates stirring vessels from small beakers (≥50 mL) up to 80 L jacketed reactors, accommodating standard laboratory glassware and stainless-steel pilot vessels. Its clamping system accepts stirring rods from 1–10 mm diameter—including PTFE-coated, glass, or Hastelloy shafts—enabling compatibility with aggressive solvents and elevated temperatures. While not certified for explosion-proof use (ATEX/IECEx), its non-sparking motor architecture and absence of electronic components in the drive head meet general safety requirements for non-hazardous atmospheres per IEC 61000-6-3 (EMC) and IEC 61000-6-2 (immunity). It supports GLP-compliant workflows through stable, repeatable torque delivery and traceable speed calibration—though it does not include built-in audit trail or 21 CFR Part 11 functionality due to its standalone analog-digital hybrid architecture.

Software & Data Management

The RW 28 digital operates as a stand-alone instrument without onboard data logging, USB, RS232, or analog output interfaces. All operational parameters—including set speed, actual speed, and error status—are displayed locally via the LED interface. For integration into automated systems, users may pair the unit with external programmable logic controllers (PLCs) or data acquisition modules using its passive analog tachometer signal (available via optional accessory cable). No proprietary software is required or provided; however, IKA’s standard documentation includes full calibration procedures, torque-speed curves, and maintenance schedules aligned with ISO/IEC 17025 metrological traceability guidelines.

Applications

• Preparation of high-viscosity formulations in pharmaceutical development (e.g., ointments, gels, suspensions)
• Mixing of ceramic and battery slurry materials requiring shear-stable dispersion
• Homogenization of polymer melts and thermoset resins prior to casting or extrusion
• Controlled agitation in bioreactor seed train expansion and media preparation
• Emulsification of food-grade oils and stabilizer blends under regulated temperature conditions
• Pilot-scale reaction monitoring where simultaneous probe insertion (pH, conductivity, temperature) is essential

FAQ

Can the RW 28 digital be used with jacketed reactors for temperature-controlled reactions?

Yes—the unit operates within an ambient temperature range of 5–40 °C and is compatible with externally temperature-regulated vessels. However, it does not provide active heating or cooling; thermal control must be managed by the reactor system.
Is the hollow shaft compatible with all standard temperature probes?

The 10.5 mm internal diameter accommodates most commercially available 6–8 mm diameter Pt100, thermocouple, or digital probe assemblies—verify probe outer diameter and sealing requirements prior to insertion.
Does the RW 28 digital support continuous operation over 8 hours?

Yes—it is rated for 100% duty cycle and features automatic thermal cutoff to prevent motor damage during extended runs.
What maintenance intervals are recommended for long-term reliability?

IKA recommends biannual inspection of the gear train lubrication, shaft runout verification, and torque calibration check—documented in the user manual per ISO 9001 preventive maintenance protocols.
Can this stirrer be mounted on third-party lab frames or custom rigs?

Yes—the rear mounting holes conform to standard M6 thread spacing (40 mm center-to-center), and the 16 mm diameter extension arm allows secure attachment to IKA, Fisher Scientific, or generic universal stands.