Fig. 1

The image of the prepared TFTC (a) and the schematic of the calibration system (b). a The photograph of the ITO/PtRh:PtRh TFTC. It was deposited on alumina substrate (75 mm × 12 mm × 0.5 mm) by magnetron sputtering. Each leg of TFTC is 63 mm in length and 1 mm in width. And the thickness of TFTC is approximately 1 μm. b The schematic of the calibration system. The cycling water was used to enlarge temperature gradient between the hot junction and the cold junction. The temperature of hot junction, T₁, and the temperature of cold junction, T₂, were measured with standard S and K type wire thermocouples mounted on the back of the substrates, respectively. The cold junction was prolonged by homogeneous wires for connecting a digital multimeter to measure the electromotive force (EMF)