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Metrology_Temperature measurement_measurement.pdf
- 1. Name: Tumpa Barman Subject:Metrology and Instrumentation Roll No: 34900724068 Department: Mechanical Sem: 4th
- 2. Temperature Measurement in Metrologyand Instrumentation
- 3. Introduction to TemperatureMeasurement • Temperature measurement is essential in various industries, including manufacturing, healthcare, and meteorology. • Accurate temperature measurement ensures quality control, safety, and efficiency in processes. • Various devices and methods are used to measure temperature based on different principles.
- 4. Temperature Scales • Fourmajor temperature scales: • Celsius (°C) • Fahrenheit (°F) • Kelvin (K) • Rankine (°R) • Kelvin is the SI unit of temperature and is commonly used in scientific measurements.
- 5. Types of TemperatureMeasuring Devices • Liquid-in-glass thermometers • Bimetallic thermometers • Thermocouples • Resistance Temperature Detectors (RTDs) • Thermistors • Infrared thermometers and pyrometers
- 6. Liquid-in-Glass Thermometers • Containsa liquid (mercury or alcohol) that expands and rises in a capillary tube. • Used in laboratories, weather stations, and medical applications. • Simple and cost-effective but has limited accuracy.
- 7. Bimetallic Thermometers • Madeof two metals with different thermal expansion rates bonded together. • When temperature changes, the strip bends due to differential expansion. • Commonly used in industrial applications and HVAC systems.
- 8. Thermocouples • Based onthe Seebeck effect, where a voltage is generated between two dissimilar metals. • Can measure a wide range of temperatures. • Types include Type K, J, T, E, and more, each with specific temperature ranges and materials.
- 9. Resistance Temperature Detectors(RTDs) • Works on the principle that electrical resistance of a metal changes with temperature. • Made of platinum (e.g., PT100 and PT1000 sensors). • High accuracy and stability but more expensive than thermocouples.
- 10. Thermistors • Semiconductor-based temperaturesensors with high sensitivity. • Two types: NTC (Negative Temperature Coefficient) and PTC (Positive Temperature Coefficient). • Used in medical devices, automotive applications, and HVAC systems.
- 11. Infrared Thermometers &Pyrometers • Measure temperature without physical contact using infrared radiation. • Used in high-temperature environments, such as furnaces and engines. • Fast response time and ideal for non-contact temperature measurement.
- 12. Calibration & Standardsin Temperature Measurement • Regular calibration ensures accuracy and reliability. • Calibration methods include comparison with standard thermometers and fixed-point calibration. • Standards include ITS-90 (International Temperature Scale of 1990) and NIST traceability.
- 13. Conclusion & FutureTrends in Temperature Sensing • Temperature measurement is vital across industries for safety, quality control, and efficiency. • Emerging trends include smart sensors, wireless temperature monitoring, and AI-based temperature analysis. • Advancements in nanotechnology and MEMS (Micro-Electro-Mechanical Systems) are improving sensor accuracy and miniaturization.