YUHUA DF-101S Integrated Heating Magnetic Stirrer

Overview

The YUHUA DF-101S Integrated Heating Magnetic Stirrer is an engineered laboratory instrument designed for simultaneous precise temperature control and robust mechanical agitation in open or sealed vessel configurations. Unlike conventional flat-plate magnetic stirrers, the DF-101S employs a radiant integrated heating architecture—where the heating element is concentrically embedded within a deep-drawn stainless steel heating well—ensuring uniform thermal flux distribution across the entire base and sidewalls of round-bottom flasks, boiling flasks, and other curved-vessel geometries. This configuration enables rapid thermal equilibration (up to three times faster than surface-heated alternatives) and minimizes axial and radial temperature gradients during exothermic or endothermic reactions. The device operates without external circulators or auxiliary thermostats, supporting direct immersion heating via water bath (≤100 °C), silicone oil bath (≤300 °C), or controlled dry-heating modes. Its thermally isolated design—featuring an aluminum heat-shield partition between the heating chamber and electronics enclosure—maintains stable electrical performance and component longevity under sustained high-temperature operation.

Key Features

• Radiant integrated heating well constructed from high-grade 304 stainless steel, formed via deep drawing for structural integrity and corrosion resistance
• DC high-torque motor delivering consistent rotational output up to 2400 rpm with low acoustic emission (<55 dB at 1 m)
• NdFeB (neodymium-iron-boron) permanent magnet rotor providing superior magnetic coupling strength, enabling reliable stirring of viscous media (up to 10,000 mPa·s) and large-volume vessels (up to 5 L with appropriate stir bar)
• High-stability resistive heating element: stainless steel-sheathed, pre-aged at 800 °C for 24 hours to eliminate thermal drift; insulation resistance certified >1000 MΩ per IEC 61010-1
• Triple-mode thermal operation: compatible with water baths (for ≤100 °C applications), silicone or mineral oil baths (for ≤300 °C synthesis), and controlled dry-heating (with appropriate vessel support)
• Modular thermal isolation system incorporating a passive aluminum heat-dissipating barrier between the heating cavity and control electronics, preventing thermal back-transfer and ensuring long-term signal stability

Sample Compatibility & Compliance

The DF-101S accommodates standard laboratory glassware including 50 mL to 5000 mL round-bottom flasks, flat-bottom beakers, and jacketed reactors (when used with compatible adapters). Its open-well geometry supports both magnetic stir bars and PTFE-coated overhead impellers (via optional mounting kits). The unit complies with GB/T 25117–2010 for general safety requirements of laboratory equipment and meets electromagnetic compatibility criteria per GB/T 18268.31–2017 (IEC 61326-2-1). While not inherently 21 CFR Part 11 compliant (as it lacks onboard data logging or user-access controls), it may be integrated into GLP/GMP workflows when paired with external validated temperature recording systems and documented SOPs for calibration and maintenance.

Software & Data Management

The DF-101S is an analog-controlled instrument with no embedded microprocessor or digital interface. Temperature regulation is achieved via calibrated bimetallic thermostat or optional external electric contact thermometer (compatible with DF-101B variant’s dedicated socket). For traceable process documentation, users are advised to pair the unit with third-party temperature dataloggers (e.g., Omega OM-DAQPRO-5300 or Testo 176 T4) connected to calibrated PT100 probes immersed directly in the bath medium. All calibration records—including stir speed verification using optical tachometry and thermal uniformity mapping per ASTM E2251—must be retained per ISO/IEC 17025 requirements for accredited laboratories.

Applications

• Synthesis of metal-organic frameworks (MOFs) requiring prolonged reflux under inert atmosphere with precise thermal ramping
• Enzymatic hydrolysis assays where viscosity changes demand consistent shear input across variable temperature profiles
• Preparation of nanoparticle colloids (e.g., Fe₃O₄, TiO₂) via sol-gel routes necessitating homogeneous nucleation conditions
• Standardization of viscosity reference oils per ASTM D445, using calibrated capillary viscometers in constant-temperature baths
• Extraction protocols (Soxhlet, maceration) where simultaneous heating and agitation improve mass transfer kinetics
• Quality control testing of polymer melts and thermoset precursors under non-isothermal curing conditions

FAQ

Can the DF-101S be used for closed-system reactions under nitrogen or argon?
Yes—provided the reaction vessel is fitted with appropriate gas inlet/outlet ports and the stir bar is chemically inert (e.g., PTFE-encapsulated or glass-coated). Ensure adequate clearance between vessel bottom and heating well to prevent localized overheating.
Is calibration certificate included with shipment?
No—calibration is performed by the end-user or an accredited third-party provider per local metrological requirements. A factory verification report confirming functional operation at 25 °C, 60 °C, and 100 °C is available upon request.
What maintenance intervals are recommended for long-term reliability?
Inspect stir bar coupling efficiency and heating well cleanliness every 200 operational hours; verify insulation resistance annually using a 500 V DC megohmmeter per IEC 62353.
Does the unit support programmable temperature ramps?
No—the DF-101S provides manual temperature setpoint control only. For ramp/soak profiles, integrate with an external PID controller and contact thermometer.
Can it accommodate custom flask geometries beyond standard round-bottom designs?
Yes—custom well inserts (e.g., conical, rectangular, or multi-port configurations) can be fabricated upon technical specification submission; lead time typically 4–6 weeks.