Microsensors

Resistance Thermometer Probes to DIN Specification

For temperatures from -220°C + 400°C+800°C

• Standardised resistance values, direct replacement without recalibration of indicator or controller


• High accuracy, excellent long-term stability


• Measurement can be transmitted over long distance without ancillary equipment


• Fast response, 50% time for approx. 1.5 second depending on probe pattern


• Available in various protective mountings


• Twin resistance thermometers available


• Favourable resistance change permits short instrument spans

Application
Resistance thermometers are usually preferred for temperature measurement and control in the range from -220°C to +800°C. The usage of resistance thermometers as temperature probes is highly successful with indicators, controllers and recorders, used in air conditioning, refrigeration, heating installations, etc. Remote temperature measurement with resistance thermometers offers the benefit of long-term accuracy, the extreme stability of the resistance element. Close resistance tolerances ensure direct interchangeability of all different patterns and fittings without recalibration provided the lead length remains unchanged.

Measuring Principle
Measurement with resistance thermometers depends on the variation with temperature of the resistance of certain metal wires. The resistance elements are produced from platinum or nickel wire, and the electrical resistance is a measure of the temperature to which the problem is exposed.

Construction
Resistance thermometers generally consist of three components:

Inserts - 6 to 8 mm dia., resistance element Ni or pt 100 Ohm at 0° C, Basic Value to DIN 43760

Operating - Ni resistance element from - 60°C to +150°C,

Temperature - Briefly to +180°C pt resistance elements from -200°C to 400°C or + 800°C