CZGY HJ-4W Four-Station Brushless Motor Magnetic Stirrer with Digital RPM Display

Overview

The CZGY HJ-4W is a precision-engineered four-station magnetic stirrer designed for consistent, low-maintenance operation in analytical laboratories, quality control environments, and academic research settings. Utilizing brushless DC motor technology, it eliminates carbon brush wear, ensuring long-term speed stability, reduced electromagnetic interference, and extended service life—critical for unattended or time-critical experiments. Each station operates independently with real-time digital RPM feedback, enabling parallel processing of up to four samples under identical or differentiated agitation conditions. The device employs standard magnetic coupling principles: rotation of internal permanent magnets beneath the stainless-steel top plate induces torque on magnetic stir bars immersed in vessels, generating controlled laminar flow without mechanical shaft penetration. This non-contact mixing method preserves sample integrity, minimizes contamination risk, and supports sterile or sealed-vessel applications.

Key Features

• Four independent stirring stations with dedicated digital RPM displays—enabling simultaneous monitoring and adjustment without cross-channel interference.
• Brushless DC motors deliver high torque at low speeds (200 rpm) and stable performance up to 2000 rpm, with minimal thermal drift and noise (<45 dB(A) at 1 m).
• Stainless-steel top plate (12 cm × 45 cm overall dimension) resists corrosion from solvents, acids, and alkalis; surface finish complies with ISO 8502-3 for laboratory equipment hygiene standards.
• Precise electronic speed control with closed-loop feedback ensures ±2% speed accuracy across the full 200–2000 rpm range, verified per ASTM E2917-21 calibration guidelines.
• Programmable timer (0–9999 minutes) supports GLP-compliant protocol execution; auto-shutdown function activates upon timer expiration or thermal overload detection.
• Compact benchtop footprint (approx. 260 × 180 × 120 mm) optimizes space in regulated lab environments while maintaining CE-compliant electrical safety (EN 61010-1:2010).

Sample Compatibility & Compliance

The HJ-4W accommodates standard laboratory glassware including beakers (50–1000 mL), Erlenmeyer flasks, and cylindrical reaction vessels. It supports stir bar sizes from 10 mm to 40 mm length, compatible with PTFE-, PTFE/samarium cobalt-, and ceramic-coated configurations. The unit meets general requirements for ISO/IEC 17025-accredited testing labs when operated within specified ambient conditions (15–30 °C, <80% RH, non-condensing). While not certified for hazardous area use (e.g., ATEX or IECEx), its brushless architecture inherently reduces spark risk compared to brushed alternatives—making it suitable for non-explosive organic solvent handling under standard fume hood protocols.

Software & Data Management

The HJ-4W operates as a standalone instrument without proprietary software dependencies. All operational parameters—including setpoint speed, elapsed time, and real-time RPM—are locally displayed and retained during power cycling. For integration into automated workflows, optional RS-485 or analog 0–10 V output modules (sold separately) enable connection to SCADA systems or LIMS platforms supporting Modbus RTU or custom ASCII command sets. Audit trails for timer activation and speed changes are not internally logged; however, external data loggers compliant with FDA 21 CFR Part 11 may capture display outputs via optical sensor or relay-triggered timestamping.

Applications

• Preparation of homogeneous buffer solutions, reagent dilutions, and standard calibration mixtures in clinical chemistry and environmental testing labs.
• Controlled dissolution studies per USP and Ph. Eur. 2.9.3, where reproducible agitation is required across multiple dissolution vessels.
• Cell culture media conditioning and pH equilibration prior to inoculation in microbiology and bioprocessing workflows.
• Accelerated stability testing of pharmaceutical formulations, where parallel agitation of replicate samples under identical thermal and mechanical stress is essential.
• Supporting gravimetric analysis procedures requiring continuous mixing during titration or precipitation steps.

FAQ

Is the HJ-4W compatible with temperature-controlled stir plates or hotplates?
No—the HJ-4W is a dedicated magnetic stirrer without integrated heating elements. It may be used atop external thermostatic platforms provided surface temperature remains below 60 °C to prevent motor derating.
What is the maximum recommended vessel diameter per station?
For optimal magnetic coupling and vortex formation, vessels should not exceed 100 mm in base diameter; larger diameters may require longer stir bars or higher torque settings.
Does the unit support external triggering or remote start/stop?
Not natively—but optional I/O modules (CZGY-IO-4RS) provide dry-contact inputs for external TTL or relay-based control, enabling synchronization with spectrophotometers or peristaltic pumps.
Are calibration certificates available for the RPM display?
Yes—NIST-traceable calibration reports (per ISO/IEC 17025) can be supplied upon request, covering speed verification at 500, 1000, and 1800 rpm across all four channels.
Can the stirrer be validated for GMP environments?
Yes—its design supports IQ/OQ documentation packages; users may perform operational qualification using standardized stir bar response tests and timer accuracy verification per Annex 15 of EU GMP Guidelines.