Resistance Thermometer Sensor

Principle of Resistance Thermometer

In general, metal electric resistance varies according to temperature changes. Platinum is more linear and carries larger temperature coefficient than most other metals with different relations, and the product therefore is suitable for temperature measurement. In adition, as the platinum carries excellent chemical and physical properties, the product can be used for a long period of time in a stable condition as a temperature measuring resistance element capable of easily and industrially obtaining accurate resistance values. The characteristics have been standardized based on intermational standards, ensuring high-accuracy temperature measurements.
The resistance thermometer is composed of resistance elements, internal conductors, insulating tube or insulating powder, protection tubes, terminal heads and other required parts. .

Features

1. Resistance elements
   The resistance thermometer element uses high-precision ceramic element(CERACOIL), provided with a MICA element created by wrapping platinum around the Mica board and FILM element fixed in a protection tube.
2. Internal lead wire
   The internal lead wire is used to connect the resistance elements and terminals. Thestandard conductor type is 3-wire system ; however, 2-wire and 4-wire types are also available. Nickel wire, silver wire and copper wires are used for the conductors.
3. Insulator
   This is used to insulate between internal lead wire and wires and to prevent short-circuit. Teflon tube, asbestos tube, magnesium oxide powder and ceramic insulation tube are used.
4. Protection tube
   This protectin tube protects resistance elements, and internal wires from surrounding conditions, to which components and terminal heads are connected. As the operating temperature, atmosphere and purposes of the protection tube vary considerably according to the temperature checking places, it is necessary to select materials and shapes which suit conditions.
5. Terminal head and terminal plate
   This terminal head is used to connect the resistance thermometer and external lead wire. It is necessary to select terminal heads of various material quality and shapes to suit the purpose of use, in addition to the Head Type(aluminium diecast)
6. Mounting attachment
   The mounting attachment is installed on the protection tube to mount the resistance thermometer to the measuring part.(For more details, refer to standard parts catalog.)