Platinum Resistance Thermometers (RTD, PRT, Pt100 Sensors)
A Platinum Resistance Thermometer, commonly referred to as RTD Sensors, PRT Sensors or Pt100 Sensors, is a type of resistance temperature sensor used for a wide variety of temperature measurement applications. There are many types of Resistance Thermometer, but typically Pt100 (made using a Platinum element with a resistance of 100 ohms @ 0ºC and typically with a 38.5 ohm fundamental interval - change in resistance over the range 0 to 100ºC), available in a wide range of designs and constructions as shown below.
We are the largest manufacturer of Platinum Resistance Thermometers (RTD sensors) in Europe. Having an enormous range of components in stock means we can make virtually any sensor you specify. We can ship custom built RTD Sensors typically within 5 days or sooner.
Typical Platinum Resistance Thermometers
Resistance Thermometers (Pt100, RTD, PRT) -Mineral Insulated

Rigid Stem

Resistance Thermometers (Pt100, RTD, PRT)

for Surface Measurements

Resistance Thermometers (Pt100, RTD, PRT)

Resistance Thermometers (Pt100, RTD, PRT)

Resistance Thermometers (Pt100, RTD, PRT)

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Resistance Thermometer Materials and Theory
Several materials are available with a predictable and stable temperature versus resistance relationship such as copper, silver and gold but platinum has considerable advantages that make it well suited to resistance thermometry.
Most industrial resistance thermometer use a platinum element with a resistance of 100 ohms at 0°C, this resistance changes as the temperature changes. Resistance Thermometers are commonly used from temperatures of -50ºC to +250ºC and are favoured over thermocouples because they have a better accuracy over this range.
A constant current is applied to the RTD and the resultant volt drop as resistance changes is measured. Assemblies wired as 2, 3 or 4-wire are available - the 3 and 4 wire versions compensating for lead resistances.
A more detailed explanation of resistance thermometer theory along with technical information and data can be found here.