Rhodium wire has a resistivity of 4.67×10-2 Ω·mm 2 /m, a tensile strength of 726 MPa, and an elongation of 46%. The smelting is carried out by high-frequency furnace argon gas, remelted 2 to 3 times, bottom injection, hot working - cold working into 0.02 mm filament. It is a good high temperature thermocouple material. The Rh-PtRh20 thermocouple has high temperature stability and does not require strict cold junction compensation. The temperature is 1800 °C.
One of the rarest metals on earth (abundance of 2 x 10 4 ppm), rhodium does not appear naturally, tending to be found with other platinum group metals. It is a hard, lustrous, silvery colored metal which is stable in air. Rhodium is inert to all acids but is attacked by fused alkalis.
Rhodium wire has high thermal and electrical conductivities and is alloyed with platinum to form the positive wire of a Pt/Rh - Pt thermocouple. Other applications of the material include its use as a plating material (to provide a hard and bright surface which is resistant to oxidation), as a catalyst and also as an alloying element, where it improves the hardness of the resulting alloy.