Question

1.which type of material(wire) is used in resistance thermometer?
2.which thermometer is more sensitive? mercury or gas
3.which range of temp. can you measure using platinum resistance thermometer?

Answer 1

1.Resistance thermometers, also called resistance temperature detectors (RTDs), are sensors used to measure temperature. Many RTD elements consist of a length of fine wire wrapped around a ceramic or glass core but other constructions are also used. The RTD wire is a pure material, typically platinum, nickel, or copper.

2.Gases are more sensitive to the temperature than the mercury. That means gas expands more than the mercury for the same increase of temperature. Hence the gas thermometer is more sensitive than mercury thermometer

3.

offer excellent accuracy over a wide temperature range (from –200 to +850 °C). Standard sensors are are available from many manufacturers with various accuracy specifications and numerous packaging options to suit most applications. Unlike thermocouples, it is not necessary to use special cables to connect to the sensor.

The principle of operation is to measure the resistance of a platinum element. The most common type (PT100) has a resistance of 100 ohms at 0 °C and 138.4 ohms at 100 °C. There are also PT1000 sensors that have a resistance of 1000 ohms at 0 °C.