quotation of characterization of material laboratory-1) measurement of electrical and thermal conductivity of copper thermal conductivity of copper unit constant current source 20-500 ma dc differential amplifier, 4 inputs 0-30 mv, resolution : 0.001 mv digital multimeter interconnecting wires 2) thermal diffusivity of brass thermal diffusivity unit regulated dc power supply 30 v, 5a max dc differential amplifier, 4 inputs 0-30 mv, resolution : 0.001 mv digital multimeter interconnecting wires.