Two wire RTD Circuit
The two wires RTD is the simplest wire configuration. One wire is attached to each side of the element. A measure can be taken by any device equipped to measure resistance, including basic Volt Ohm Meters (VOM).
This is the least accurate way of measuring temperature, due to the fact that the lead wire resistance is in series with the sensing element.
The lead wire is at a different temperature than the sensing element and also has different resistance verses temperature characteristics.
The longer the lead wire greater will be the effect on the measurement.