acoustic temperature transducer

Recent developments in temperature measurement have encouraged researchers to develop low-cost, simple structure, computerized generic transducers for environmental monitoring and industrial process control. The research presents a computerized technique which allows to measure temperature according to the variation of acoustic velocity (frequency) in a closed waveguide. Signal conditioning and processing was carried out using LabVIEW (G Language) VIs. In order to evaluate the time characteristic of the transducer its response was compared with that of a reference detector (PT 100) for the same step input. Static characteristics of the transducer show a quasi-linear relationship between the measured temperature and the resonance frequency. Results of practical experiments show that in order to improve the response curve of the transducer and decrease the rising time interval it is advisable to implement thin-wall glass tubes or another material with lower thermal impedance.