16-02-2010, 03:36 PM
hi i want details of this topic
16-02-2010, 03:36 PM
hi i want details of this topic
19-06-2013, 12:09 PM
Temperature Sensors
Temperature Sensors[.pptx (Size: 229.32 KB / Downloads: 17) Types of Temperature Sensors Thermocouples Resistance Temperature Detectors (RTDs) Thermistors Semiconductors Thermocouples Two wires of different metal alloys. Converts thermal energy into electrical energy. Requires a temperature difference between measuring junction and reference junction. Easy to use and obtain. Thermocouple Applications Plastic injection molding machinery Food processing equipment Deicing Semiconductor processing Heat treating Medical equipment Industrial heat treating Packaging equipment Resistance Temperature Detectors (RTDs) Wire wound and thin film devices. Nearly linear over a wide range of temperatures. Can be made small enough to have response times of a fraction of a second. Require an electrical current to produce a voltage drop across the sensor Thermistors A semiconductor used as a temperature sensor. Mixture of metal oxides pressed into a bead, wafer or other shape. Beads can be very small, less than 1 mm in some cases. The resistance decreases as temperature increases, negative temperature coefficient (NTC) thermistor. Semiconductor Applications Hard Disk Drives Personal Computers Electronic Test Equipment Office Equipment Domestic Appliances Process Control Cellular Phones CONCLUSION In this application note , the concept and usage of different temperature sensors are discussed . Among these temp. sensors 1. Thermocouple gives the fastest response to temp. change 2. RTD is most suitable over time , most accurate temp. sensor. 3. Thermistor has the highest sensitivity to small temp. change. |
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