We have several models of data loggers that are suitable for use with RTD’s. RTD sensors provide improved temperature measurement accuracy over thermocouples. The main tradeoff is that they have a more limited temperature measurement range than thermocouples.
An RTD works by changing resistance in a very predictable way in a proportion to changes in temperature. To make the measurement, the data logger will source a known current through the RTD and measure the voltage across it. From this it can calculate the resistance and then convert the resistance to temperature. Because the resistance of the lead wires which attach the sensor to the data logger can cause measurement errors, 3 or 4 wire RTD’s can be used. These allow the data logger to compensate for the effects of this resistance and subtract it from the measured value to improve the measurement accuracy.
For more information, click here for the RTD Temperature Recorder Page. For a brief tutorial on sensors for temperature measurements, please click here for the Data Logger Tutorial Page on our CAS Dataloggers Web Site.