Investigation of stability of ultrasonic system for gas flow velocity measurement

Abstract

On the basis of experimental investigation of ultrasonic system for gas flow velocity measurement it was revealed that the stability and repeatability of results of slow gas flow velocity measurements depends on the mechanical stability of equipment which is used for the gas flow creation and on the stability of the gas flow which is being created. The repeatability and stability of measuring results are influenced by the natural convection of the gas in the measuring spoolpiece and by the zero drift of the ultrasonic meter. The most influential factor which influences the zero drift of ultrasonic system for gas flow velocity measurement it is the instability of temperature of the measuring spoolpiece. After the stabilisation of temperature of the measuring spoolpiece and after sustaining it at the desired level with an accuracy of +0.05° C. the zero drift of ultrasonic gas flow velocity meter was diminished to the level Dv<0.5…1 mm/s during the 24 hour period. It enebles one to decrease the errors of the gas flow velocity measurement and to expand the limits of application of ultrasonic meters especially in the range of the slow gas flows.