Fig. 2

Measurement results of dual-beam Pd sensors and calibration results with on-site Pd thermocouples. a Voltage response under different heating powers of five different single-layered temperature sensors. The top x-axis shows the calibrated temperature difference. b Measurement results of two Pd sensors with width configurations of 800–80 and 500–80 nm. The ΔS values of the two sensors are obtained from our previous work [20]. c ΔS values of the sensors with different narrow beams from our previous work [20]. The wide beam is fixed at 100 μm in width, and the width of the narrow beam varies from 80 nm to 10 μm. The data are plotted in log-log scale. The orange line shows the quintic polynomial fitting of the data. The dashed blue lines indicate the method of calculating ΔS for a Pd sensor with a width configuration of 310 and 80 nm