Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back Exception of a number of the hydrodynamic components of the random error of acoustic flowmeters A.Z. BADALOV, A.M. IZMAYLOV Article is devoted to the analysis of mechanisms of formation of hydrodynamic components of a casual error by acoustic flow meters of the pulse principle of work. The hydrodynamic influences brought in primary converter of a flow meter from out of are the reason of formation of errors. Influences are brought by the section of pipes having considerable roughness, knees and pipeline with stop valves which openings through passage are displaced from a longitudinal axis of primary converter. The specified influences lead to the following consequent: to deviations of local speeds in acoustic channels from the average speed of a stream; discontinuous fall of the first half wave of a reception signal or of the discontinuous moment of registration of a first half wave reception signal to the second, with the second on the third etc. For elimination of hydrodynamic errors a number of practical recommendations are given in article. The design and manufacturing techniques of the device for jet straightening and extinction of a turbulence of a stream of the measured environment at an entrance and exit to a measuring section of primary converter are offered; the design of the piezoelectric converter which provides the radiated (reception) signal which duration doesn’t exceed one period of resonant frequency of a piezoelectric element are offered. Analytical expressions for a choice of diameter of a piezoelectric element in depending from diameter of a measuring section of primary converter and number of acoustic channels of a flow meter are offered. Keywords: pulse acoustic flow meter; systematic error; random component of an error; hydrodynamic component of a random error; comparator of a reception signal; stream turbulence, asymmetry of a stream of the measuring environment. Contacts: Е-mail: arif.badalov@mail.ru Pp. 06-16.