CZGY SHA-2A Refrigerated Magnetic Stirring Water Bath

Overview

The CZGY SHA-2A Refrigerated Magnetic Stirring Water Bath is an integrated laboratory thermal platform engineered for simultaneous precise temperature regulation, active magnetic agitation, and closed-loop liquid circulation. Unlike conventional water baths or standalone chillers, the SHA-2A employs a dual-mode thermoregulatory architecture—combining resistive heating elements with a sealed refrigeration circuit (R134a-based compressor system) to achieve stable operation across the full 0–100 °C range. Its core function relies on convective heat transfer within deionized or distilled water medium, coupled with four independently mounted magnetic stirrers that generate uniform rotational torque via permanent magnet coupling through the stainless steel bath floor. This design enables reproducible kinetic control during temperature-sensitive protocols such as enzymatic reaction kinetics, polymer dissolution, buffer equilibration, and low-temperature crystallization studies—common requirements in analytical chemistry, pharmaceutical development, and materials science laboratories.

Key Features

• Four-channel synchronized magnetic stirring: Each stirrer operates at identical RPM (adjustable 0–1200 rpm), eliminating inter-vessel variability during multi-sample comparative experiments.
• Dual-mode temperature control: Integrated Peltier-assisted precooling and high-efficiency compressor cooling enable rapid transition from ambient to sub-zero setpoints, while 1200 W heating ensures fast ramp-up above room temperature.
• High-stability thermal chamber: 304 stainless steel inner tank (welded seamless construction) resists corrosion from aqueous buffers, organic solvents, and mild acids; external enclosure features electrostatically applied epoxy-polyester powder coating for abrasion and chemical resistance.
• Intelligent digital interface: Backlit LCD display with real-time monitoring of setpoint, actual bath temperature, stirring speed, and system status flags (e.g., “Cooling Active”, “Heating Active”, “Low Water Alert”).
• Circulating coolant loop: Integrated 50 W peristaltic pump supports external jacketed reactor cooling or auxiliary temperature control of ancillary equipment (e.g., condensers, probes).
• Safety-certified architecture: Over-temperature cutoff, dry-run protection, ground-fault circuit interruption (GFCI), and automatic compressor delay to prevent thermal shock to refrigerant cycle.

Sample Compatibility & Compliance

The SHA-2A accommodates standard laboratory glassware including 50–500 mL beakers, Erlenmeyer flasks, and cylindrical sample vessels up to 18 cm height. Its open-bath configuration allows direct visual monitoring and easy access for pipetting or sampling without disassembly. The unit complies with IEC 61010-1:2010 for electrical safety in laboratory equipment and meets CE marking requirements for electromagnetic compatibility (EMC Directive 2014/30/EU). While not certified for cleanroom use, its non-shedding stainless interior and absence of lubricants or gaskets make it suitable for ISO/IEC 17025-accredited testing environments where trace contamination must be minimized. It supports GLP documentation workflows through manual log entry of setpoints, durations, and operator IDs—though native electronic audit trail functionality is not embedded.

Software & Data Management

The SHA-2A operates as a standalone instrument with no proprietary software dependency. All operational parameters are configured and monitored locally via the front-panel interface. For integration into automated lab systems, optional RS-232 or analog 0–5 V output modules (sold separately) enable connection to SCADA platforms, LIMS interfaces, or custom Python/LabVIEW data acquisition scripts. Temperature and stirring speed values can be logged externally at user-defined intervals (e.g., every 10 seconds) with timestamp synchronization. No firmware updates or cloud connectivity are supported; calibration verification is performed using NIST-traceable RTD probes in accordance with ASTM E1137/E1137M for thermometer accuracy assessment.

Applications

• Controlled-rate dissolution testing of APIs under pharmacopoeial conditions (USP <711>).
• Multi-vessel enzymatic assays requiring identical thermal and hydrodynamic environments (e.g., kinase activity profiling).
• Polymer solution viscosity conditioning prior to rheological measurement (ISO 16520).
• Low-temperature hybridization of nucleic acid probes in molecular biology workflows.
• Pre-equilibration of chromatographic mobile phases and standards in HPLC method development.
• Stabilization of thermolabile reagents (e.g., restriction enzymes, fluorescent dyes) during preparation and storage.

FAQ

What type of water should be used in the bath?

Deionized or distilled water is required to prevent mineral scale buildup on heating elements and stirrer couplings. Tap water or softened water is not recommended due to ion-induced corrosion and reduced thermal conductivity.
Can the SHA-2A maintain sub-zero temperatures without antifreeze?

No. The bath is designed for aqueous operation only. Adding ethylene glycol or other cryoprotectants voids the warranty and risks damage to the stainless tank and pump seals.
Is individual speed control available for each stirrer?

No. All four stirrers operate at the same RPM, adjusted via a single rotary encoder. Independent control is not supported by the current hardware architecture.
How often should the circulating pump filter be cleaned?

The inline filter (located upstream of the pump head) should be inspected and rinsed with deionized water after every 200 hours of continuous operation or before initiating any long-duration experiment (>12 h).
Does the unit meet FDA 21 CFR Part 11 requirements?

No. The SHA-2A lacks electronic signature capability, audit trail generation, and user-access controls required for Part 11 compliance. It is intended for research-use-only applications unless validated with supplementary procedural controls.