CZGY SHJ-4A Digital Constant-Temperature Magnetic Stirring Water Bath

Overview

The CZGY SHJ-4A Digital Constant-Temperature Magnetic Stirring Water Bath is an integrated laboratory thermal platform engineered for simultaneous precise temperature regulation, uniform heat distribution, and robust magnetic agitation across multiple sample vessels. It operates on the principle of resistive heating via embedded high-efficiency tubular heaters combined with PID-controlled feedback loops to maintain thermal stability within ±0.5°C across its operational range (ambient +5°C to 100°C). Unlike basic water baths, the SHJ-4A incorporates four independent stirring zones—each driven by a sealed, brushless DC motor—enabling concurrent, programmable agitation of up to four beakers or flasks without cross-contamination or mechanical coupling. Its modular design supports scalable experimental setups in synthetic chemistry, enzymatic assays, dissolution testing, and sample pre-conditioning workflows where reproducible thermal-mechanical input is critical.

Key Features

• Four-zone independent magnetic stirring system with adjustable speed (0–2400 rpm), each controlled via dedicated digital interface for process isolation and repeatability.
• PID digital temperature controller with real-time LED display, auto-tuning capability, and over-temperature safety cutoff to prevent thermal runaway.
• Quadruple 400 W heating modules ensure rapid heat-up and stable thermal equilibrium—even under variable load conditions—across the full 4-compartment bath volume.
• Stainless steel inner bath (φ22 cm × 13 cm per zone) with seamless welds and electropolished finish for chemical resistance, ease of cleaning, and long-term integrity in aqueous and mildly corrosive media.
• Cold-rolled steel outer housing with epoxy powder coating provides mechanical durability, electrical insulation, and protection against ambient moisture and lab spills.
• Integrated timer function (0–999 minutes) supports unattended operation with automatic shutdown, aligning with GLP-compliant workflow requirements.
• Modular accessory system includes four stainless steel support rods, four universal condenser clamps, and eight interchangeable circular lid rings (five per set), enabling flexible vessel mounting and vapor containment.

Sample Compatibility & Compliance

The SHJ-4A accommodates standard laboratory glassware including 50–500 mL beakers, Erlenmeyer flasks, and round-bottom flasks (up to 250 mL per zone). Its open-bath architecture allows direct immersion of reaction vessels while maintaining compatibility with reflux, distillation, and hydrolysis configurations. All wetted surfaces comply with ISO 8573-1 (purity class 4) for non-reactive contact with aqueous solutions. The unit meets CE marking requirements for electromagnetic compatibility (EN 61326-1) and low-voltage safety (EN 61010-1), and its temperature control algorithm adheres to ASTM E2422–22 guidelines for thermal stability verification in laboratory heating equipment.

Software & Data Management

While the SHJ-4A operates as a standalone instrument with front-panel digital controls, its temperature and timer parameters are fully traceable via built-in non-volatile memory that retains last-used settings after power cycling. For laboratories requiring audit trails, optional RS-485 communication (via external converter) enables integration into centralized monitoring systems compliant with FDA 21 CFR Part 11 when paired with validated SCADA or LIMS platforms. All calibration events—including temperature sensor verification using NIST-traceable reference thermometers—are documentable through user-generated log sheets aligned with ISO/IEC 17025 internal calibration procedures.

Applications

• Controlled-temperature synthesis reactions requiring homogeneous mixing and thermal consistency (e.g., esterification, polymerization initiations).
• Dissolution testing per USP and Ph. Eur. 2.9.3 protocols, where bath uniformity and agitation synchronization directly impact release rate accuracy.
• Enzyme kinetics studies at defined temperatures (e.g., 37°C mammalian, 60°C thermophilic), leveraging independent zone control to run parallel conditions.
• Cell culture media pre-warming and reagent equilibration prior to sterile handling, minimizing thermal shock during transfer.
• Calibration of liquid-in-glass thermometers and RTDs using fixed-point water baths validated per ISO 17025 Clause 6.5.2.

FAQ

What is the maximum recommended vessel height for use with the included support rods?
Standard rods support vessels up to 300 mm in height; extension rods (optional) accommodate up to 450 mm.
Can the SHJ-4A operate continuously for 24 hours?
Yes—the unit is rated for continuous duty at ≤85°C; prolonged operation at 100°C requires periodic visual inspection of water level and heater integrity.
Is the temperature sensor calibrated at the factory?
Each unit ships with a certificate of conformance indicating calibration against a PT100 reference probe at three points (25°C, 50°C, 75°C); field recalibration is supported using external standards.
Does the stirring function remain active during timer-based shutdown?
No—both heating and stirring deactivate simultaneously upon timer expiration to prevent dry-run damage.
Are replacement bath inserts available for individual zones?
Yes—stainless steel bath inserts (φ22 × 13 cm) are offered as spare parts (CZGY P/N: SHJ-BI-04) for maintenance or contamination isolation.