Platinum Resistance Temperature Detectors / Sensors [ PT - 100 ]

Platinum Resistance Temperature Detectors or RTDs for short, are wire wound and thin film devices that measure temperature. The hotter they become, the larger or higher the value of their electrical resistance.

They, in the case of platinum known variously as prts and prt100s, are the most popular rtd type, nearly linear over a wide range of temperatures and some small enough to have response times of a fraction of a second. They are among the most precise temperature sensors available with resolution and measurement uncertanties or ±0.1 °c or better possible in special desions.

Usually they are provided encapsulated in probes for temperature sensing and measurement with an external indicator, controller or transmitter, or enclosed inside other devices where they measure temperature as a part of the device's function, such as a temperature controller or precision thermostat.

Where |t| is the absolute value of the rtd's temperature in °c.
Below are examples of these tolerances for a nominal 100 ohm (at 0°c) platinum rtd.
The din standard recognizes tolerance classes, they are:

Din class a tolerance : ± [0.15 + 0.002 * | t | ] °c
Din class b tolerance: ± [ 0.30 + 0.005 * | t | ] °c

Thin film element sizes : 1 x 1.2 / 1.5 x 5 / 2 x 2.3 / 2 x 5 / 2 x 10 / 2 x 15
Cwramic wire wound.Sizes : 0.7 x 15 / 0.9 x 15 / 1.4-1.5-1.6 x 12-15-25 / 2.8 x 12-15-15-30
Glass epoxy : sizes : 2.8 x 12-15-15-30

Thermal ribbon . Sizes : square-round-rectangle in different sizes.
Temperature ranges from -200c to +600c-800c

Basically used in dairies-textiles-boilers-cold storages-bearings-laboratories-chemicals-oil tanks-freezers-automations etc. Where there are temperatures below 600 to -200c & where the importance are given for fast [quick] sensing response.