How to Maintain and Calibrate a Laser Thermal Conductivity Analyzer

This guide outlines practical procedures for maintaining and calibrating a laser thermal conductivity analyzer to ensure reliable measurements and extend instrument life. Routine maintenance Cleaning - Optical components: The laser window, lenses, and other optics are prone to dust and grease. Clean them regularly (e.g., weekly, adjusted to environment) using lint-free swabs or lens paper. For stubborn contamination, lightly apply anhydrous ethanol, taking care to prevent liquid ingress into optical assemblies. - Sample stage: After each test, remove debris and dust from the stage. If samples are corrosive or volatile, clean immediately to prevent corrosion and carryover effects on subsequent measurements. Environmental control - Temperature and humidity: Place the instrument in a controlled environment at 18–25 ℃ and 40%–60% relative humidity. Avoid moisture that can cause corrosion or short circuits, and prevent prolonged exposure to high temperatures that degrade performance and lifespan. - Dust protection: Keep the instrument in a clean, low-dust area. If dust levels are high, use a dust cover when the instrument is idle to reduce contamination. Mechanical checks - Sample mounting: Periodically inspect clamps, lifters, and other fixtures for smooth motion. If sticking or looseness occurs, tighten hardware or apply appropriate lubrication. As a guideline, check clamp screws quarterly and lubricate as needed to ensure stable operation. - Cables and connections: Inspect power and signal cables for wear, cracking, or aging. Replace damaged cables promptly to maintain electrical safety and stable communication. Calibration methods 1) Standard sample calibration - Select certified standards: Choose standards appropriate to the instrument’s range and application. For solids, use certified metal or ceramic blocks with known thermal conductivity values and high accuracy. - Test and compare: Measure the standard following the normal procedure, then compare results with the certified value. If a deviation exists, adjust instrument parameters (e.g., laser power, thickness correction factor) per the user manual to minimize error. A typical acceptance target is a post-calibration error not exceeding ±1%. 2) Reference instrument comparison - Prepare a reference: When possible, use a recently calibrated, higher-accuracy analyzer of the same type as a reference, or a trusted thermal property system such as a guarded hot plate thermal conductivity tester. - Synchronous testing: Measure the same sample on both instruments under comparable conditions. If differences arise, adjust the parameters of the instrument under calibration until the results align with the reference within the allowable error range. 3) Temperature calibration (for instruments with temperature measurement) - Use a temperature standard: Employ a high-precision temperature standard, such as a secondary standard platinum resistance thermometer. Bring the instrument’s temperature sensor (e.g., thermocouple or RTD) into contact with the standard and compare readings. - Apply corrections: If a bias is observed, open the temperature settings and adjust temperature compensation or apply linear correction so the instrument’s display matches the standard. Accurate temperature calibration is essential for reliable measurements of temperature-dependent properties such as specific heat capacity. By following these maintenance routines and calibration practices, laboratories can maintain data integrity, reduce downtime, and ensure consistent, traceable measurements with their laser thermal conductivity analyzers.

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