Ultrasonic temperature measurement and uses in optical spectroscopy and calorimetry

摘要

A process and apparatus for the photothermal and/or calorimetric investigation of gaseous, liquid and solid measuring material is based on the detuning of an ultrasonic resonator (1). The latter has an ultrasonic transmitter (2) and an ultrasonic receiver (3), which face one another. The signal from the receiver is analyzed by an analyzer (5) as to its amplitude or phase position which gives, as a result of the temperature dependence of the sonic velocity, information on thermal changes in the ultrasonic resonator designed as a gas cell or calorimeter. The present apparatus makes it possible to detect gases or to calorimetrically investigate the material to be investigated, particularly light- conducting elements (5), such as light fibers.