ULTRASONIC CURRENT METER

摘要: PURPOSE:To know a flow velocity, by detecting the phase difference of transmitting and receiving signals counting number shifts necessary for always holding output signal shift register to center an input multiplying cycle calculate ultrasonic propagation time. CONSTITUTION:The apparatus UT are changed over on basis (a) voltage control transmittent USC change- device TMT (e) is shaped rectangular one shaping circuit RCV generate edge (h) pulse (g) generator ED. The frequency multiplied multiplier FMUL set (i) clock shifted SFT content (p). divided into three respectively reference l, m, n from PHS. phases p-n compared with PHC made slow if appearance thereof initial period while fast final count pulses sent UD AND (m( showing that present in central calculated perform addition SIGMA subtraction DELTA according forward or reverse direction velocity fed back NF product DELTAoutput width CAL obtain time and, because distance L between known, obtained.