Why is platinum used in platinum resistance thermometer?

The most reproducible type of sensor is made from platinum because it is a stable unreactive metal which can be drawn down to fine wires but is not too soft. The length and diameter of the platinum wire used in a thermometer are often chosen so that the resistance of the device at around 0 ºC is 100 ohms.

How does resistance vary with temperature in platinum and nickel?

Nickel elements have a limited temperature range because the amount of change in resistance per degree of change in temperature becomes very non-linear at temperatures over 300 °C (572 °F). Pure platinum has α = 0.003925 Ω/(Ω·°C) in the 0 to 100 °C range and is used in the construction of laboratory-grade RTDs.

Why Nickel is used in RTD?

Nickel is less chemically-inert that platinum and so is less stable at higher temperatures. Glass passivation can extend the useful temperature range to 200°C, but the nickel RTD is normally used for sensing in the environmental temperature range and in clear air.

Why is platinum used in PRT how high a temperature can this thermometer read?

It measures temperature using the resistance of a piece of pure platinum wire. Platinum is typically used due to its stability and ability to be reduced to fine wires. A PRT is one type of RTD. The difference is the material it constructed with, and hence it gets its own name PRT.

How does a platinum resistance thermometer measure temperature?

The resistance of platinum increases linearly with the temperature, and this property of the metal is used for measuring the temperature. The resistance of the platinum is measured by passing the alternating or direct current through it.

Where are platinum resistance thermometers used?

The platinum resistance thermometer is a versatile instrument for temperature measurement in the range from — 200° to 1000°C. It is used both for precision measurements of the highest accuracy and for routine industrial work.

Why copper is used in RTD?

Copper RTDs have the best resistance to temperature linearity of the three RTD types, and copper is a low cost material. However, copper oxidizes at higher temperatures. Copper is limited to a measurement range of -200… +260°C.

Why is platinum used for industrial temperature measurement Mcq?

Explanation: In industrial applications, platinum is used due to its accuracy in providing measurements. It is also reproducible. Platinum element can be used for the measurement of temperatures of about 1000 K. Platinum, nickel and copper are the commonly used metals for measuring temperature.

What is the accuracy of platinum resistance thermometer?

In general, PRTs can have high accuracy (0.01 °C), stability, and repeatability across a wide range of temperatures from -200 °C to 500 °C.

What is the material used in platinum resistance thermometer?

A platinum resistance thermometer consists of a coil of platinum wire wound on a ceramic former. One of its advantages is that it can be used over a very wide range of temperatures, from −100 °C to several hundred degrees Celsius.