concentrically arranged as viewed in its cross section optionally it may have the component conductors superposed in non circular shape e g in elliptic shape as illustrated in fig5 in this diagram the symbols 22 23 and 24 denote a first superconductor a normal conductor and a second superconductor respectively now a test model for working the present invention will be described below with reference to the schematic structural diagram of fig6 the temperature detection unit 1 used in this test model is obtained by suitably shaping a nbti wire clad in copper popularly known as 34 copper clad superconducting wire 34 which is rather easily available the copper coat on the core of nbti wire 70 u03bc in diameter is chemically corroded to a thickness of about 2 u03bc in the middle portion of the periphery of the copper coat normal conductor 3 remaining on the periphery of the nbti wire first superconductor 2 pbsn solder is deposited in a length of about 2 mm in the axial direction so as to give rise to a second superconductor 4 the temperature detection unit 1 thus constructed is set in position on an article 21 subjected to temperature measurement and usually kept at a temperature below 4 2 k a power source current source 25 is disposed between one terminal of the first superconductor 2 and the second superconductor via a standard resistor 22 through the medium of a superconducting quantum interference device squid 24 designed to enhance the sensitivity a squid controller 26 is disposed between the other terminal of the first superconductor 2 and the.