Ultrasonic flowmeter geometric size calibration

YI Jin-ping， BAO Min
（Faculty of Mechanical Engineering & Automation， Zhejiang Sci-Tech University， Hangzhou 310018， china）

Abstract： Aiming at this problem that the measuring tool and calculation method improper selection reduce geometric size calibration accuracy in dry calibration of ultrasonic flowmeter，the internal diameter micrometer was choosen to measure the channel length， diameter and channel angle of ultrasonic flowmeter from the angle of measuring tools and correlation. And it was calculated respectively the three factors of the relative uncertainty.Finally，it was compared with calculating relative error of 0.067% when only considering the measurement repeatability，and it's 0.070% when considering the measurement tools and correlation. So a conclusion was gotten that the measurement tools and measuring correlation were important factors affecting the geometry calibration accuracy.The results indicate that this method can improve the certainty for dry calibration.
Key words：ultrasonic； flowmeter； geometric size calibration； calibration accuracy； measurement repeatability；measuring tool；measurement correlation