This paper presents an ultrasonic thermometry state of the art study and shows principle of the ultrasonic thermometry through experiments with an ultrasonic thermometer prototype. The study covers a brief ultrasonic temperature measurement research history and focuses on recent revelations in this field. The thermometer prototype is constructed to be portable and usable for educational presentations. Its principle, performance and ultrasonic temperature measurements results are described in the experimental part. Keywords-ultrasonic thermometry; air temperature measurement; time of flight; ultrasonic thermometer;I.

This paper presents portable ultrasonic thermometer developments in humidity and transducer inertia correction. It describes humidity effect on the speed of sound and a method for its correction. Transducer inertia is also described and shown on real measurements, along with a corrective method. Experimental measurement results are presented. Also, audible sound thermometry and its potential advantages and drawbacks are discussed and a simple audible sound preliminary measurement is conducted.