| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas meter superior in cost and suitable for a size reduction as a charging gas meter configured to measure heat quantity.SOLUTION: A gas meter includes: a flow path 3 into which gas 2 flows; an ultrasonic sensor 41 for detecting a pair of propagation times when an ultrasonic wave propagates in a flow of the gas 2; a temperature sensor 42 for measuring temperature of the gas 2; acoustic velocity deriving means 21 for determining acoustic velocity of the gas 2 from the pair of propagation times; and flow velocity deriving means 11 for determining flow velocity. The gas meter further includes: instantaneous heat quantity deriving means 22 for determining instantaneous heat quantity of the gas based on an acoustic velocity-heat quantity relationship index from the acoustic velocity of the gas 2 determined by the acoustic velocity deriving means 21; passing volume per unit time deriving means 13 for deriving a passing volume per unit time of the gas 2 based on the flow velocity; and passing heat quantity per unit time deriving means 23 for deriving the heat quantity of the gas 2 from the instantaneous heat quantity and the passing volume per unit time. |
