GAS PHYSICAL PROPERTY-MEASURING DEVICE AND METHOD

PROBLEM TO BE SOLVED: To obtain an easy-to-use gas physical property-measuring device where, for example, a timing for replacing operation cannot be limited. SOLUTION: A device is provided with a measurement pipe 70 where a gas to be measured is introduced and flows in the direction of a pipe axis inside, at the same time a detection part of a pair of ultrasonic transceiver 15a in parallel with the flow of the gas to be measured in the measurement pipe while they oppose each other, and a sound speed-deriving means 18 for capturing propagation time where ultrasonic waves are propagated in the flow of the gas to be measured from one ultrasonic transceiver 15a to the other 15a bi-directionally and for obtaining the sound speed of the gas to be measured according to the obtained pair of propagation time. Further, the device is provided with at least one of calory-deriving means 20a for obtaining the amount of generated heat of the gas to be measured according to a sound speed obtained from the sound speed-deriving means 18, a specific gravity-deriving means 20b for obtaining the specific gravity of the gas to be measured, or a Wobbe index-deriving means 20c for obtaining the Wobbe index of the gas to be measured.