CZGY SHJ-8AS Digital Constant-Temperature Magnetic Stirring Water Bath

Overview

The CZGY SHJ-8AS Digital Constant-Temperature Magnetic Stirring Water Bath is an eight-position parallel thermal processing platform engineered for precise temperature maintenance and simultaneous magnetic agitation across multiple samples. Designed around a Couette-type stirring principle—where rotation of a magnetic stir bar within a fluid generates controlled laminar flow—the system ensures uniform heat transfer and homogeneous mixing in each well without mechanical shaft penetration. Each of the eight independently controlled wells features integrated digital PID temperature regulation, real-time RPM monitoring, and brushless DC motor-driven stirring—eliminating carbon brush wear and minimizing electromagnetic interference during sensitive assays. The unit operates within a calibrated range of ambient +5°C to 100°C, with thermal stability maintained at ±0.5°C under steady-state conditions, making it suitable for applications requiring reproducible thermal kinetics, such as enzyme incubation, solubility testing, dissolution profiling, and sample equilibration prior to HPLC or spectrophotometric analysis.

Key Features

• Eight independent heating and stirring stations, each with dedicated digital temperature setpoint and real-time RPM display
• Stainless steel inner bath chamber and fully encapsulated stainless steel work surface—resistant to corrosion, easy to decontaminate, and compliant with GLP cleaning validation protocols
• Brushless DC stirring motors delivering stable torque from 0 to 2000 rpm, with speed accuracy of ±1 rpm and low acoustic emission (<45 dB at 1 m)
• Digital PID temperature controller with adjustable timer function (0–999 minutes) for both heating and stirring cycles
• Individual drain ports per station for rapid, contamination-free medium exchange; no cross-well fluid migration
• Modular accessory support: includes eight stainless steel support rods, eight condenser clamps, and eight 5-ring circular aluminum lids for reflux or vapor containment
• 400 W resistive heating elements per well—optimized for rapid thermal recovery after sample loading and minimal temperature gradient across bath volume

Sample Compatibility & Compliance

The SHJ-8AS accommodates standard laboratory glassware including 25–250 mL round-bottom flasks, beakers, and test tubes (up to Ø22 cm diameter × 13 cm height per well). Its open-bath architecture supports integration with external condensers, sensors, or pH probes via standardized clamp mounts. All electrical components comply with IEC 61010-1:2010 safety standards for laboratory equipment. The stainless steel construction meets ASTM A240/A240M requirements for corrosion-resistant austenitic alloys. While not certified for Class I Division 1 hazardous locations, the unit is rated for use in general-purpose chemical laboratories operating under ISO/IEC 17025-accredited quality systems. Temperature calibration reports traceable to NIST-certified reference thermometers are available upon request for audit readiness.

Software & Data Management

The SHJ-8AS operates via embedded microcontroller firmware with no external PC dependency. All operational parameters—including set temperature, actual bath temperature, target RPM, measured RPM, and remaining timer duration—are displayed on dual-line LED indicators per station. Though not equipped with USB or Ethernet connectivity, the device supports manual data logging via external thermocouple readers (e.g., Omega HH309A) or time-lapse thermal imaging. For regulated environments, users may implement supplementary electronic lab notebook (ELN) integration using timestamped operator logs aligned with 21 CFR Part 11-compliant audit trails generated by third-party documentation platforms.

Applications

• Multi-sample dissolution testing per USP and Ph. Eur. 2.9.3, with synchronized temperature ramping and agitation across eight vessels
• Enzyme kinetic studies requiring strict thermal control during substrate conversion (e.g., lactate dehydrogenase activity at 37°C)
• Pre-analytical sample conditioning for ICP-MS, AAS, or UV-Vis quantification where matrix homogeneity and thermal history impact precision
• Accelerated stability trials under controlled thermal stress (e.g., ICH Q1A(R2) long-term and intermediate condition screening)
• Synthesis support for small-molecule reactions requiring inert-atmosphere reflux with magnetic stirring
• Calibration of liquid-in-glass thermometers and RTD probes against reference standards in multi-point verification workflows

FAQ

Is the SHJ-8AS compatible with external temperature probes for independent verification?
Yes—each well includes a 3 mm diameter probe port adjacent to the stirrer position, allowing insertion of PT100 or Type K thermocouples without obstructing magnetic coupling.
Can the unit maintain temperature uniformity when all eight wells are loaded with different volumes?
Within ±0.8°C across wells at 60°C steady state (tested with 50 mL vs. 200 mL water loads), provided vessels are centered and stir bars are appropriately sized.
Does the system support programmable ramp-hold profiles?
No—temperature and speed are manually set per station; ramping requires external controllers or sequential manual adjustment.
What is the maximum recommended flask size per well?
Round-bottom flasks up to 250 mL (Ø22 cm max outer diameter, ≤13 cm height) ensure optimal magnetic coupling and thermal contact with the bath base.
Are replacement stir bars and lids available as spare parts?
Yes—CZGY supplies PTFE-coated stir bars (15 mm × 5 mm, 20 mm × 6 mm), aluminum ring lids (5-ring configuration), and silicone O-rings for lid sealing under separate part numbers.