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 Application of vortex flowmeter 
 JHLU vortex flowmeter series is mainly used for industrial pipe medium fluid flow measurement, such as gas, liquid, vapor and other media. Pressure loss is characterized by small, measuring range, high precision in the measurement conditions are not nearly the volume density of the fluid flow, pressure, temperature, viscosity and other parameters. No moving mechanical parts, so high reliability and little maintenance. Long-term stability of the instrument parameters. Vortex flowmeter using piezoelectric stress sensors, high reliability, can be -20 ℃ ~ +250 ℃ operating temperature range. With analog standard signal, but also digital pulse signal output, easily supporting the use of computers and other digital systems is a more advanced and ideal flow meter. 
 Vortex flowmeter 
 Set in the fluid vortex triangular columnar body alternately from both sides of the bluff body to generate a regular vortex, this vortex is called Carmen vortex, as shown, the vortex downstream of the bluff body listed in the non-symmetrically arranged . 
 The occurrence frequency of the vortex set f, the average flow rate of the measured medium, the bluff body surface facing the flow width d, the body of the path to D, you can get the following relationship: 
 f = SrU1 / d = SrU / md (1) 
 Where U1 - on both sides of the bluff body mean flow velocity, m / s; 
 Sr - Strouhal number; 
 m - on both sides of the bluff body bow area and the ratio of pipe cross-sectional area 

 Qv is the volume flow pipeline 
 qv = πD2U / 4 = πD2mdf/4Sr (2) 
 K = f / qv = [πD2md/4Sr] -1 (3) 
 Where K - the instrument flow coefficient, the number of pulses / m3 (P/m3). 
 K addition to the bluff body, the relevant geometry of the pipeline, but also with the Strouhal number related. Strouhal number of dimensionless parameters, it is with the bluff body shape and Reynolds number on Figure 2 shows the cylindrical bluff body of the Strouhal number and the pipe Reynolds number diagram. The figure shows that in ReD = 2 × 104 ~ 7 × 106 range, Sr can be considered as a constant, which is the normal operating range instrument. When the measurement of gas flow, VSF formula for the flow meter