Editing Resistance thermometer (section)

===Two-wire configuration===
[[File:twowire.gif|Two-wire resistance thermometer]]

The simplest resistance-thermometer configuration uses two wires. It is only used when high accuracy is not required, as the resistance of the connecting wires is added to that of the sensor, leading to errors of measurement. This configuration allows use of 100&nbsp;meters of cable. This applies equally to balanced bridge and fixed bridge system.

For a balanced bridge usual setting is with R2 = R1, and R3 around the middle of the range of the RTD. So for example, if we are going to measure between {{convert|0|and|100|C|F|0}}, RTD resistance will range from 100 Ω to 138.5 Ω. We would choose R3 = 120 Ω. In that way we get a small measured voltage in the bridge.