MKN CJ-882A High-Power Magnetic Hotplate Stirrer
| Power Supply | 220 V ±10%, 50 Hz ±2% |
|---|---|
| Speed Range | 0–2200 rpm, continuously variable |
| Stirring Power | 250 W |
| Max. Stirring Volume | 10 L |
| Heating Power | 300 W |
| Timer Range | 0–120 min or continuous operation |
| Temperature Control Range | RT to 100 °C (digital display) |
| Stir Bar Material | PTFE-coated neodymium magnet assembly |
| Motor Type | Brushless DC motor |
Overview
The MKN CJ-882A High-Power Magnetic Hotplate Stirrer is an engineered solution for demanding laboratory mixing and temperature-controlled homogenization tasks. Designed around Couette flow principles, it delivers consistent torque transfer via magnetic coupling between the rotating stir bar and the internal drive magnet array—enabling efficient agitation without mechanical shaft penetration. This architecture eliminates seal wear and contamination risk, making it suitable for sealed-vessel applications in analytical sample preparation, reagent synthesis, dissolution testing, and buffer equilibration. Its integrated heating plate provides uniform thermal distribution across standard round-bottom flasks and beakers (up to 10 L), while the brushless DC motor ensures low acoustic emission (<45 dB at 1 m), high rotational stability, and extended service life under continuous load.
Key Features
- High-torque brushless DC motor delivering stable rotation from 0 to 2200 rpm with smooth, stepless speed control via precision potentiometer interface
- Digital PID temperature controller with ±0.5 °C accuracy over the full 25–100 °C operating range; real-time display on LED panel with auto-calibration capability
- Robust ceramic-coated aluminum heating plate (130 mm diameter) offering rapid thermal response and resistance to chemical splashes and thermal shock
- PTFE-encapsulated neodymium stir bars (standard 40 mm × 8 mm) rated for continuous operation up to 100 °C and compatible with acidic, alkaline, and organic media
- Programmable digital timer supporting both fixed-duration cycles (0–120 min) and indefinite operation modes—ideal for overnight reactions or standardized dissolution protocols
- Overheat protection circuitry and stall detection logic prevent coil damage during viscosity spikes or dry-heating events
Sample Compatibility & Compliance
The CJ-882A accommodates a wide range of vessel geometries—including borosilicate glass flasks (50 mL to 10 L), stainless steel reactors, and polypropylene containers—provided magnetic coupling remains effective (minimum wall thickness ≤ 12 mm for glass, ≤ 8 mm for metal). It complies with IEC 61010-1:2010 for electrical safety in laboratory equipment and meets EMC requirements per EN 61326-1:2013. While not certified for Class I Div 1 hazardous locations, its sealed electronics and non-sparking motor make it suitable for general-purpose use in ISO 17025-accredited labs performing routine QC/QA procedures. No modifications are required to support GLP-compliant workflows when paired with external audit-trail-enabled data loggers.
Software & Data Management
The CJ-882A operates as a standalone instrument with no embedded firmware or network connectivity. All operational parameters—speed setpoint, target temperature, elapsed time, and active mode—are retained on the front-panel display and manually recorded. For traceable documentation, users may integrate the unit into validated systems via analog 0–10 V output signals (optional accessory port) for speed and temperature feedback, enabling synchronization with LIMS or ELN platforms that support analog input logging. When used in FDA-regulated environments, manual entry into 21 CFR Part 11–compliant electronic notebooks satisfies data integrity requirements for method development and batch release testing.
Applications
- Preparation of homogeneous polymer solutions prior to rheological or viscometric analysis
- Controlled-temperature dissolution studies per USP and Ph. Eur. 2.9.3
- Buffer equilibration for HPLC mobile phase preparation and column conditioning
- Accelerated stability testing of pharmaceutical suspensions under isothermal agitation
- Chemical synthesis requiring inert-atmosphere stirring with external condenser attachment
- Microbiological media preparation where precise thermal ramping and mixing consistency impact growth kinetics
FAQ
What is the maximum recommended viscosity for reliable operation at 2200 rpm?
At full speed, optimal performance is maintained for Newtonian fluids with dynamic viscosity below 10,000 mPa·s (e.g., 60% glycerol/water at 25 °C); higher viscosities require reduced speed to sustain torque and thermal margin.
Can the unit maintain temperature stability during prolonged stirring of high-heat-capacity solutions?
Yes—the 300 W heater and optimized thermal mass design achieve ±0.8 °C stability over 4-hour runs with 5 L water loads under ambient conditions of 20–25 °C.
Is calibration of the temperature sensor traceable to NIST standards?
The built-in Pt100 sensor is factory calibrated; users may perform field verification using a NIST-traceable reference thermometer inserted directly into the stirred medium.
Does the device support external control via RS-232 or USB?
No—CJ-882A is a manually operated analog instrument without digital communication interfaces; remote operation requires third-party relay modules or programmable logic controllers.
What maintenance intervals are recommended for long-term reliability?
Brushless motor requires no scheduled maintenance; annual inspection of heating plate surface integrity and periodic cleaning of ventilation grilles with compressed air are advised.
