CZGY HJ-9A Digital Display Constant-Temperature Magnetic Stirrer
| Brand | CZGY |
|---|---|
| Origin | Jiangsu, China |
| Manufacturer Type | Direct Manufacturer |
| Product Category | Domestic Lab Equipment |
| Model | HJ-9A |
| Instrument Type | Magnetic Stirrer |
| Max Stirring Volume | 1 L × 9 Stations |
| Speed Range | 0–2000 rpm |
| Temperature Control Range | Ambient +5°C to 100°C |
Overview
The CZGY HJ-9A Digital Display Constant-Temperature Magnetic Stirrer is an engineered multi-station laboratory instrument designed for simultaneous, independent temperature-controlled magnetic stirring across nine discrete positions. It operates on the principle of rotating magnetic fields generated by internal permanent magnets driven by low-noise DC motors, coupling with magnetic stir bars placed in sample vessels to induce homogeneous fluid motion. Unlike single-position stirrers, the HJ-9A integrates nine thermally isolated heating and stirring units—each equipped with a dedicated motor, temperature sensor, and control circuit—enabling parallel processing of multiple samples under identical or individually optimized thermal and agitation conditions. This architecture supports reproducible kinetic studies, reagent preparation workflows, dissolution testing, and standardized sample conditioning in quality control (QC), pharmaceutical development, and academic research laboratories.
Key Features
- Nine independent stirring stations, each supporting up to 1 L volume with PTFE-coated magnetic stir bars (recommended)
- Adjustable speed range from 0 to 2000 rpm per station, controlled via individual analog rotary dials—engineered for stable low-speed torque and high-speed consistency
- Digital LED temperature display with ±1.0°C accuracy across the full control range (ambient +5°C to 100°C); each station features a dedicated Pt100 RTD sensor and proportional-integral (PI) temperature regulation
- Stainless steel heating plates (12 cm diameter × 9) with uniform heat distribution and rapid thermal response; total heating power: 1800 W (200 W × 9)
- Robust aluminum alloy housing with ventilation slots and thermal cutoff protection per channel, compliant with IEC 61010-1 safety requirements for laboratory electrical equipment
- Modular design facilitates maintenance and long-term reliability—motor assemblies and heating elements are field-replaceable without soldering or specialized tools
Sample Compatibility & Compliance
The HJ-9A accommodates standard laboratory glassware including beakers (50–1000 mL), Erlenmeyer flasks, and cylindrical reaction vessels compatible with magnetic stir bar dimensions up to 40 mm length × 8 mm diameter. It supports aqueous, organic, and mildly corrosive solutions; use of borosilicate glass and chemically inert stir bars is recommended for extended chemical exposure. The unit meets general-purpose lab safety standards under GB/T 29303–2012 (Chinese national standard for magnetic stirrers) and aligns with functional expectations of ASTM D7985–21 (Standard Guide for Laboratory Stirring Practices). While not certified for GMP manufacturing environments, its stable thermal and rotational performance supports GLP-compliant documentation when integrated into validated SOPs.
Software & Data Management
The HJ-9A operates as a standalone hardware platform without embedded microcontroller-based data logging or PC connectivity. Temperature and speed settings are manually configured and visually monitored via front-panel digital displays. For traceability in regulated environments, users may integrate external USB data loggers (e.g., Omega OM-DAQPRO-5300 series) connected to thermocouple inputs at each station’s output terminals—enabling time-stamped recording aligned with 21 CFR Part 11 audit trail requirements when paired with compliant software platforms such as LabArchives ELN or DeltaTrak Validator. No firmware updates or driver installation are required.
Applications
- Parallel dissolution testing of solid dosage forms under USP conditions
- Multi-vessel buffer equilibration in protein purification workflows
- Simultaneous pH adjustment and mixing during titration method development
- Accelerated stability study sample conditioning per ICH Q1A(R2)
- Preparation of calibration standards and reference materials across analytical chemistry labs
- Cell culture media pre-warming and homogenization prior to sterile filtration
FAQ
Is the HJ-9A suitable for viscous solutions such as glycerol or polymer solutions?
Yes—its 25 W per motor rating provides sufficient torque for low-to-medium viscosity fluids (< 500 mPa·s) at speeds ≥ 300 rpm; for higher viscosities, use larger-diameter stir bars and reduce target speed to maintain laminar flow.
Can the unit be operated inside a fume hood?
Yes, provided ambient humidity remains below 80% RH and airflow does not exceed 0.5 m/s directly over the heating plates to avoid thermal drift and condensation on electronics.
Does the HJ-9A support external temperature probe input for vessel-specific feedback control?
No—temperature regulation is based solely on built-in plate-mounted RTDs; external probe integration requires third-party PID controllers with analog output capability.
What is the expected service life under continuous operation?
With proper load management and periodic cleaning of heating plate surfaces, the unit demonstrates >15,000 hours MTBF (mean time between failures) per station, consistent with ISO 14155:2020 guidance for laboratory equipment durability assessment.
