A primary acoustic thermometer can be realized by measuring the speed of sound in a low pressure monoatomic gas and extrapolating the results to zero-pressure. The thermodynamic temperature can be determined by measurements of the acoustic and microwave resonance frequencies of a single cavity of simple geometry. Microwave data are used to deduce the thermal expansion of the cavity under vacuum. Owing to its high accuracy, this method is suitable for the determination of deviations between the Kelvin thermodynamic temperature scale and the International Temperature Scale of 1990 (ITS 90). The performance of the acoustic thermometer, which is currently under development at IEN and IMGC, in terms of achievable precision and accuracy and some preliminary results are reported.
Acoustic Measurements of the thermodynamic temperature between 234 and 400 K / Benedetto, G; Brunetti, Luciano; Gavioso, Roberto; Spagnolo, R; Marcarino, P; Merlone, A; Tiziani, A.. - (2001). (Intervento presentato al convegno 17th International Congress on Acoustics tenutosi a Rome-Italy nel 2-7 September 2001).
Acoustic Measurements of the thermodynamic temperature between 234 and 400 K
BRUNETTI, LUCIANO;GAVIOSO, ROBERTO;Merlone A;
2001
Abstract
A primary acoustic thermometer can be realized by measuring the speed of sound in a low pressure monoatomic gas and extrapolating the results to zero-pressure. The thermodynamic temperature can be determined by measurements of the acoustic and microwave resonance frequencies of a single cavity of simple geometry. Microwave data are used to deduce the thermal expansion of the cavity under vacuum. Owing to its high accuracy, this method is suitable for the determination of deviations between the Kelvin thermodynamic temperature scale and the International Temperature Scale of 1990 (ITS 90). The performance of the acoustic thermometer, which is currently under development at IEN and IMGC, in terms of achievable precision and accuracy and some preliminary results are reported.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
