DEVICE FOR MONITORING RESIDUAL QUANTITY OF GAS

摘要

<P>PROBLEM TO BE SOLVED: To provide a device for monitoring the residual quantity of gas which reduces the number of processes for setting a warning level. Ž<P>SOLUTION: Acoustic transducers TD1 and TD2 are provided in a gas flow path 3 separately from each other in the flow direction. CPU 15a controls the acoustic transducers TD1 and TD2 and measures a propagation time T1 of an ultrasonic signal from one to the other of the paired acoustic transducers TD1 and TD2 and a propagation time T2 of the ultrasonic signal from the latter to the former. The CPU 15a further determines a propagation time T3 of the ultrasonic signal between the paired acoustic transducers TD1 and TD2 from which the effect of the speed of a running fluid of the gas is removed by adding up the propagation times T1 and T2 and dividing the result by two. The CPU 15a issues warning when the propagation time T3 from which the variation due to an increase or decrease of the temperature of the gas flow path 3 is removed based on a detected temperature of a temperature sensor 19 exceeds the warning level. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž