Sanpu HSJ Series Digital Constant-Temperature Water Bath Magnetic Stirrer

Overview

The Sanpu HSJ Series Digital Constant-Temperature Water Bath Magnetic Stirrer integrates precision thermostatic water bath functionality with independent magnetic stirring across multiple stations. Engineered for reproducible thermal and mechanical control in analytical and preparative laboratory workflows, this instrument operates on the principle of resistive heating combined with permanent-magnet-driven stir bar rotation—enabling simultaneous temperature stabilization and homogeneous mixing within aqueous or low-viscosity liquid samples. Unlike standalone hotplates or immersion circulators, the HSJ series provides uniform heat distribution via stainless-steel water bath chambers and eliminates localized overheating risks associated with direct-contact heating. Its digital PID temperature controller ensures stable setpoint maintenance under dynamic load conditions, making it suitable for applications requiring both thermal equilibration and agitation—such as dissolution testing, enzyme kinetics, buffer preparation, and standard solution dilution. Designed for continuous operation in regulated environments, the unit complies with general electrical safety requirements for Class I laboratory equipment (IEC 61010-1).

Key Features

• Digital LED temperature display with ±1 °C accuracy across a 0–100 °C range, enabling precise thermal protocol execution
• Independent speed control (0–2400 rpm) per station via dedicated rotary dials—no cross-channel interference
• Modular station architecture: configurable from 1 to 10 stirring positions; each station features isolated motor drive and thermal coupling
• Stainless-steel water bath tank resistant to corrosion and thermal fatigue; compatible with deionized water, glycerol-water mixtures, and low-concentration aqueous buffers
• Intelligent dual-indicator system: green LED signals active heating; red LED confirms thermal equilibrium—no manual intervention required during steady-state operation
• Robust thermal insulation and overtemperature cutoff protection (auto-shutdown at ≥105 °C) to prevent dry-run damage
• Grounded metal chassis meeting IEC 61010-1 safety standards for laboratory use

Sample Compatibility & Compliance

The HSJ series accommodates standard laboratory glassware including beakers (25–500 mL), test tubes, and volumetric flasks. It supports sample volumes from 10 mL up to 500 mL per station, provided containers are magnetically responsive (e.g., borosilicate glass with PTFE-coated stir bars). The water bath medium must remain non-conductive and non-volatile under operating conditions; ethanol or acetone are strictly prohibited. While not certified to ISO/IEC 17025 or GLP-specific validation protocols out-of-the-box, the instrument’s digital temperature logging capability (when interfaced with external data acquisition systems) supports traceable calibration records compliant with internal QA/QC procedures. Users performing regulated work (e.g., pharmacopeial dissolution per USP ) should validate temperature uniformity and stirring consistency per ASTM E2912–22 guidelines.

Software & Data Management

The HSJ series operates as a stand-alone analog-digital hybrid instrument without embedded firmware or network connectivity. Temperature setpoints and speed values are entered manually via front-panel thumbwheel switches and displayed on a 3-digit LED screen. For audit-trail compliance in GxP environments, optional RS-232 or USB-to-serial adapters (sold separately) enable real-time temperature and RPM streaming to third-party SCADA or LIMS platforms. Raw time-series data can be exported for post-hoc analysis in MATLAB, Python (Pandas), or Excel. All parameter changes—including setpoint adjustments and power cycling—are reflected instantaneously on the display, supporting manual documentation per FDA 21 CFR Part 11 Annex A principles when paired with controlled electronic notebooks.

Applications

• Standardization of pH and conductivity reference solutions in environmental and clinical labs
• Accelerated stability studies requiring concurrent heating and mixing (e.g., polymer solubilization, surfactant micelle formation)
• Preparation of homogeneous calibration standards for atomic absorption spectroscopy (AAS) and ICP-OES
• Cell culture reagent warming and buffer equilibration prior to sterile filtration
• Teaching laboratories: demonstration of Arrhenius kinetics, heat transfer coefficients, and rheological behavior of Newtonian fluids
• Quality control workflows in food, pharmaceutical, and petrochemical sectors where batch-to-batch reproducibility is governed by SOPs referencing fixed temperature–agitation profiles

FAQ

Is the HSJ series compatible with non-aqueous bath media such as silicone oil?

No. The stainless-steel bath is designed exclusively for water-based or water-glycerol mixtures. Silicone oil exceeds maximum operational viscosity limits and may impair thermal sensor response.

Can I operate a single station while others remain inactive?

Yes. Each station has independent power gating—disabling one station does not affect temperature stability or motor performance of adjacent units.

What maintenance is required to ensure long-term temperature accuracy?

Annual verification using a NIST-traceable RTD probe is recommended. Clean the bath chamber after each use to prevent mineral buildup; descale with 5% citric acid solution if hardness deposits occur.

Does the unit support external temperature probes for sample-in-bath monitoring?

Not natively. However, the bath lid includes pre-drilled ports (M6 thread) for retrofitting PT100 or thermistor probes connected to external dataloggers.

Is CE or UL certification available for export to North America or the EU?

The base model meets IEC 61010-1 general safety requirements. Region-specific certifications (UL 61010-1, EN 61010-1) require factory-installed modifications and third-party testing—contact Sanpu’s international division for certified configurations.