Measurement method and measuring device null of gaseous fuel automobile

摘要

PURPOSE:To rapidly and accurately measure the calorific value of gas by performing calibration by compression factor and calculating true mol. wt. from the density of gas measured in the state of constant temp. and pressure and calculating the calorific value therefrom. CONSTITUTION:City gas G in a measurement pipe 11 is held at the constant temp. and pressure by a reducing valve 12 and a heat exchanger 13, etc., of a gas holding part. The density of the city gas is measured by a gas density measuring meter 6. On the other hand, the relation of a compression factor for the predictive mol. wt. of the gas to be measured at the same temp. and pressure is previously obtained by a preliminary test and stored in the memory part 19 of an arithmetic device 17. Thereby the true mol. wt. is obtained and the calorific value is calculated. As a result, the calorific value of gas is accurately obtained in a short time of only the time for measuring the density of gas and performing arithmetic treatment.