Abstract
A temperature measurement method utilizing wedge waves is proposed and demonstrated experimentally. The method is based on the principle that the propagation velocity of wedge waves depends on the temperature of the medium. First, the temperature dependence of the wedge wave velocity is quantified by measuring the round-trip propagation time. Next, the temperature distribution along the longitudinal direction of the wedge is reconstructed using the one-dimensional heat conduction equation in the form of a finite difference method. In the experiment, an aluminum wedge with a length of 120 mm, thickness of 15 mm, and apex angle of 30° was heated from one end while wedge waves were transmitted and received from the opposite end. The temperature at the heated end, where no temperature sensor was installed, was estimated from the measured propagation time of the wedge wave. The temperature resolution of the method at room temperature is obtained as approximately 0.7 °C. The obtained temperature distributions were compared with the reference temperatures measured by thermocouples installed at multiple positions along the wedge. The maximum errors between the proposed method and the thermocouple measurements were 2.46, 0.802, and 1.31 °C at three positions, confirming high measurement accuracy. The results indicate that the proposed method enables remote temperature sensing without requiring multiple sensors or optical access. This study demonstrates the feasibility of wedge-wave-based thermometry for practical use in environments where direct temperature measurement is difficult or unsafe.
