Stuart CB300 & SB300 Large-Capacity Analog-Controlled Electric Heating Plates

Overview

The Stuart CB300 and SB300 are large-format, analog-controlled electric heating plates engineered for robust, repeatable thermal processing in analytical, preparatory, and quality control laboratories. Designed for consistent conductive heating without electromagnetic interference or open flames, these units serve as foundational tools for sample evaporation, digestion, solvent reflux, drying, and controlled thermal conditioning of reaction vessels. The CB300 utilizes a high-purity glass-ceramic top plate—chemically inert, non-porous, and resistant to strong acids, alkalis, and organic solvents—enabling direct contact with aggressive reagents during acid digestion protocols (e.g., EPA Method 3050B, ISO 11466). In contrast, the SB300 employs a precision-machined aluminum-silicon alloy surface optimized for rapid thermal response and exceptional lateral heat uniformity—ideal for applications requiring fast ramp rates and minimal thermal lag, such as solvent removal or pre-heating multi-vessel blocks. Both models feature a 300 × 300 mm footprint and support vessels up to 10 L capacity, accommodating standard round-bottom flasks, tall-form beakers, digestion tubes, and custom jigs.

Key Features

• High-temperature capability: CB300 achieves up to 450 °C; SB300 operates up to 300 °C—validated across full load range with ≤3 °C surface temperature deviation (measured per ASTM E220 at 100 mm grid spacing)
• Dual-material platform strategy: Glass-ceramic (CB300) offers Class A chemical resistance per ISO 8502-1 and zero leachable ion contribution; aluminum-silicon alloy (SB300) delivers >95% thermal conductivity efficiency relative to pure aluminum while maintaining mechanical hardness >85 HB
• Analog potentiometer control with tactile feedback: Provides stable, drift-free setpoint maintenance without software dependency—critical for GLP environments where firmware validation is constrained
• Integrated safety architecture: Visual over-temperature indicator (LED flash ≥50 °C surface temp), automatic cut-off upon thermal runaway detection, and spill-resistant housing compliant with IP22 ingress protection
• Low-profile, rigid chassis: 105 mm height enables integration beneath fume hoods or within modular lab benches; reinforced base minimizes vibration transmission during magnetic stirring synchronization

Sample Compatibility & Compliance

These heating plates accommodate borosilicate glass (e.g., Pyrex®, Duran®), PTFE-coated vessels, quartz crucibles, and ceramic digestion cups without surface degradation. The CB300’s glass-ceramic surface meets ISO 10993-5 cytotoxicity requirements for indirect contact with biological samples. Both units conform to IEC 61010-1:2010 for laboratory electrical equipment safety and carry CE marking under UKCA/UKCA+ framework. They are routinely deployed in workflows aligned with USP , ISO/IEC 17025, and EPA SW-846 methods—particularly for open-vessel hotplate digestion prior to ICP-OES or AAS analysis. No calibration certificate is supplied ex-factory; users are advised to perform periodic verification using NIST-traceable surface thermometers (e.g., Fluke 62 MAX+) per internal SOPs.

Software & Data Management

As analog-operated instruments, the CB300 and SB300 do not incorporate digital interfaces, data logging, or remote connectivity. This design eliminates cybersecurity exposure vectors and simplifies 21 CFR Part 11 compliance pathways in regulated environments where electronic records are not required. Temperature stability is verified manually via calibrated probe placement at multiple locations across the heating zone, with documentation retained as paper-based or scanned PDF logs. For labs requiring audit-ready traceability, Stuart recommends pairing these units with standalone temperature validation systems (e.g., DeltaTrak FlashLink® or Ellab TrackSense® Pro) to generate time-stamped thermal profiles.

Applications

• Open-vessel acid digestion of soils, sediments, and biological tissues (HNO₃/HF/HClO₄ mixtures)
• Controlled evaporation of organic extracts prior to GC-MS injection
• Pre-heating and holding of large-volume calibration standards (1–10 L volumetric flasks)
• Thermal conditioning of polymer melts and viscous resins in material science labs
• Support heating for reflux condensers in synthetic organic chemistry workflows
• Stabilization of pH electrode storage solutions and buffer equilibration baths

FAQ

Do the CB300 and SB300 support external temperature probes for closed-loop control?

No—these are open-loop analog devices with no input ports or PID feedback circuitry. External probe integration requires third-party controllers compatible with 0–10 V or 4–20 mA analog signals.
Can I use these plates under a laminar flow hood?

Yes—low electromagnetic emission profile and absence of fan-assisted cooling make them suitable for Class II biosafety cabinets and horizontal laminar flow hoods, provided adequate clearance (≥100 mm) is maintained around perimeter vents.
Is the glass-ceramic surface repairable if scratched?

No—scratches compromise chemical resistance and cleanability. Stuart recommends replacing the entire top plate assembly (P/N STU-CB300-PLATE) rather than attempting polishing or coating.
What is the recommended cleaning protocol for the aluminum-silicon surface?

Wipe with isopropanol-dampened lint-free cloth after cooling to ambient. Avoid abrasive pads or chloride-containing cleaners to prevent pitting corrosion.
Are replacement power cords available with UK BS1363 or EU Schuko plugs?

Yes—Stuart supplies certified cord sets (P/N STU-PC-UK or STU-PC-EU) rated for continuous 1200 W operation at 230 V AC.