Answer Happy

Thermocouples are made from joining two wires with differentcompositions. When heated, the differences in thetemperature dependence on resistivity results in a predictablepotential difference across the junction allowing a temperaturemeasurement. If you connect the thermocouple to the readoutbackwards, you get erroneous measurements, so it is important toknow which wire is which even though they lookidentical. One way is to flick the wires and see howthey respond. Softer wires will plastically deform,while stiffer wires will spring back when `flicked`. If you had athermocouple made from wires of Pt metal and a Pt/Rh wire (bothwires look identical), explain how the flick test would be usefulfor identifying each wire.