HH-S Digital Constant-Temperature Oil Bath

Overview

The HH-S Digital Constant-Temperature Oil Bath is a precision thermal management instrument engineered for stable, uniform, and controllable heating of samples immersed in heat-transfer media—primarily silicone oil, mineral oil, or high-temperature synthetic fluids. Operating on resistive heating elements coupled with a microprocessor-based PID temperature controller, the unit maintains setpoint accuracy within ±0.3 °C across its full operating range (ambient to 300 °C), making it suitable for applications requiring extended thermal stability without active circulation or external recirculation pumps. Unlike water baths, the HH-S is specifically designed to withstand elevated temperatures beyond 100 °C, eliminating vapor pressure limitations and enabling consistent thermal conditioning of reaction vessels, viscometers, calibration standards, and material test specimens.

Key Features

• Robust stainless-steel inner chamber (280 × 280 × 300 mm) with corrosion-resistant finish for long-term compatibility with organic heat-transfer oils
• Digital LED display with real-time temperature readout and intuitive keypad interface for setpoint entry and parameter adjustment
• PID-controlled heating system delivering high reproducibility and minimal overshoot during ramp-up and steady-state operation
• 2500 W high-power heating element optimized for rapid thermal equilibration and recovery after sample insertion
• Over-temperature safety cutoff with independent mechanical thermostat to prevent uncontrolled thermal excursion
• Stable platform design with non-slip base and reinforced housing to support heavy glassware and metal fixtures under prolonged operation

Sample Compatibility & Compliance

The HH-S accommodates standard laboratory glassware—including round-bottom flasks (up to 2 L), U-tube viscometers, capillary tubes, and metal calibration blocks—within its open-bath configuration. Its maximum working temperature of 300 °C aligns with ASTM D445 (kinematic viscosity), ISO 3104, and USP requirements for high-temperature bath calibration. While the unit itself does not carry CE or UL certification out-of-the-box, it complies with IEC 61010-1 general safety principles for laboratory electrical equipment when operated per manufacturer instructions. For GLP/GMP environments, users may integrate optional data loggers (e.g., compliant with FDA 21 CFR Part 11) via analog output terminals for audit-ready temperature traceability.

Software & Data Management

The HH-S operates as a standalone analog-controlled instrument without embedded software or network connectivity. However, its 0–5 V or 4–20 mA analog output port enables seamless integration with third-party data acquisition systems (e.g., LabVIEW, MATLAB, or SCADA platforms) for continuous temperature logging, trend analysis, and automated alarm triggering. Optional RS485 Modbus RTU communication modules are available through authorized distributors, supporting remote setpoint adjustment and real-time status polling in multi-unit lab configurations. All recorded thermal profiles meet minimum ALCOA+ criteria (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available) when paired with validated DAQ hardware and SOP-defined procedures.

Applications

• Calibration of thermometers, RTDs, and thermocouples per ISO/IEC 17025-accredited protocols
• Thermal conditioning of polymer melts prior to rheological testing (e.g., Brookfield or TA Instruments rheometers)
• Controlled heating of chemical reactions requiring precise isothermal profiles above 100 °C
• Viscosity measurements using capillary or rotational viscometers under standardized bath conditions (ASTM D445, ISO 2555)
• Accelerated aging studies of lubricants, adhesives, and elastomers at elevated temperatures
• Pre-heating of metal test coupons for tensile or hardness evaluation per ASTM E10 or E18

FAQ

What types of heat-transfer fluids are compatible with the HH-S oil bath?
Silicone oils (e.g., Dow Corning 200 Fluid series), polyalphaolefins (PAOs), and high-flash-point mineral oils meeting ASTM D92 specifications are recommended. Avoid glycols, water, or low-boiling solvents due to volatility and degradation risks above 150 °C.

Can the HH-S be used for circulating applications?
No—the HH-S is a static immersion bath without an integrated pump or external circulation port. For forced-convection applications, consider a recirculating oil bath chiller or a separate external pump manifold.

Is the temperature sensor calibrated traceable to NIST standards?
The built-in PT100 sensor is factory-calibrated; however, end-user NIST-traceable calibration requires periodic verification using a certified reference thermometer (e.g., Fluke 1523 or Hart 1550) per ISO/IEC 17025 procedures.

Does the HH-S support programmable ramp-soak profiles?
No—this model features only single-setpoint PID control. Multi-step thermal profiles require external programmable controllers interfaced via analog input/output terminals.

What maintenance is required for long-term reliability?
Regular inspection of the oil level, cleaning of the chamber interior to prevent carbon buildup, and annual verification of thermal cut-off functionality are advised. Replace heating element gaskets every 2–3 years in continuous-use environments.