Langbo HH-S Digital Constant-Temperature Oil Bath

Overview

The Langbo HH-S Digital Constant-Temperature Oil Bath is a precision-engineered thermal platform designed for stable, uniform heating of samples immersed in oil or high-boiling-point liquids. Unlike water baths limited to 100 °C, this unit employs resistive heating elements integrated into a corrosion-resistant stainless steel bath chamber, enabling continuous operation up to 300 °C—critical for applications requiring elevated thermal energy without phase transition interference. Its operating principle relies on direct conductive heat transfer from the heated bath medium (e.g., silicone oil, mineral oil, or heat-transfer fluids) to sample containers such as reaction flasks, test tubes, or sealed vials. The digital PID temperature controller delivers real-time feedback regulation, minimizing overshoot and maintaining thermal equilibrium within ±0.5 °C across the full ambient-to-300 °C range. This stability meets typical requirements for controlled decomposition studies, solvent reflux, polymerization initiation, and catalyst activation protocols commonly performed in academic, pharmaceutical, and materials research laboratories.

Key Features

• Digital PID temperature controller with LED display for precise setpoint entry and real-time monitoring of actual bath temperature
• Stainless steel bath tank construction ensures long-term resistance to thermal oxidation and chemical exposure from common heat-transfer oils
• Adjustable temperature range spanning ambient conditions to 300 °C—validated for sustained operation at maximum setpoint without thermal drift exceeding specification
• Thermal stability of ±0.5 °C under static (non-circulating) conditions, verified per ISO/IEC 17025-compliant calibration procedures using traceable Pt100 reference probes
• Multiple standard bath volumes available: 6 L, 12 L, 20 L, and 30 L configurations—each engineered with optimized heater-to-volume ratio for rapid thermal equilibration
• Over-temperature protection circuit automatically de-energizes heating elements if sensor fault or runaway condition is detected
• Front-panel accessible power switch and independent heater enable/disable toggle for operational safety and energy management

Sample Compatibility & Compliance

The HH-S accommodates standard laboratory glassware including round-bottom flasks (up to 2 L), graduated cylinders, and immersion thermometers. Its open-bath design permits direct insertion of reaction vessels with minimal clearance constraints. While not certified to UL/CSA or CE for standalone safety compliance, the unit conforms to general electrical safety principles outlined in IEC 61010-1 for laboratory equipment. It supports GLP-aligned experimental workflows when used with documented calibration records and routine verification using NIST-traceable reference thermometers. Although lacking active circulation, its thermal homogeneity profile—measured at ≤±0.8 °C vertical gradient over 10 cm depth—satisfies ASTM D217 and ISO 6743-9 viscosity testing prerequisites when paired with appropriate bath media.

Software & Data Management

The HH-S operates as a standalone analog-digital hybrid instrument with no embedded firmware, network interface, or data logging capability. Temperature setpoints and current readings are displayed locally via a 4-digit LED screen. For integration into regulated environments (e.g., GMP or FDA 21 CFR Part 11 workflows), external validation must be performed using calibrated data loggers capable of time-stamped temperature acquisition. Users are advised to maintain manual logs or implement third-party acquisition systems compliant with ALCOA+ data integrity principles. Routine performance qualification includes daily verification of setpoint accuracy and weekly assessment of stability under load using reference standards traceable to national metrology institutes.

Applications

• Controlled thermal decomposition of organic compounds and metal-organic frameworks (MOFs)
• High-temperature solvent-based extractions and Soxhlet-style reflux setups
• Catalyst pre-treatment and thermal activation in heterogeneous catalysis research
• Viscosity measurement support for high-melting-point polymers and bituminous materials
• Calibration of temperature-sensitive sensors and transducers above 100 °C
• Accelerated aging studies of elastomers and thermosetting resins

FAQ

Does the HH-S support external temperature probe input for sample-specific monitoring?
No—the HH-S uses only its built-in immersion sensor for bath temperature feedback. External probe connectivity is not supported.
Can it be used with water below 100 °C?
Yes, though prolonged use near 100 °C may accelerate evaporation; water is recommended only for short-duration, low-temperature protocols.
Is the bath tank removable for cleaning or media replacement?
Yes—the stainless steel tank is mechanically secured and fully detachable without tools, facilitating thorough cleaning and oil change procedures.
What type of oil is recommended for operation at 250–300 °C?
High-purity silicone oil (e.g., Dow Corning 200 Fluid, 50 cSt) or synthetic polyalkylene glycol (PAG)-based heat-transfer fluids meeting ASTM D6722 specifications are recommended.
Does the unit include a calibration certificate?
No—calibration documentation must be obtained separately through accredited third-party service providers or internal metrology labs.