A product range and scope of 
 A. XFV series full pipe piezoelectric vortex flow meter 
 Two. XFV series insertion the piezoelectric vortex flow meter 
 3. XFV3 series full pipe type capacitance vortex flow meter 
 4. XFV3 series into the capacitance vortex flow meter 
 5 XFV / 3 series of battery-powered vortex flow meter 
 6. Submersible / body vortex flow meter (protocol order) 
 7. The records of the multi-function curve Totalizer instrument with the compensation function of the P / T, the Chinese LCD 
 8. Intelligent Flow Totalizer, digital display 
 XFV/XFV3 Vortex flow meter is widely used in petroleum, chemical, metallurgy, heat, textile, paper and other industries on the superheated steam, saturated steam, compressed air and gases (oxygen, nitrogen, hydrogen, natural gas, coal gas, etc.), water and liquid (such as: the measurement and control of water, gasoline, alcohol, benzene, etc.). 

 2 works 
 Set in the fluid non-streamline vortex shedder (resistive fluid) from the bluff body alternately on both sides to generate two rules of the vortex, this vortex called Kaman Vortex, as shown in (a) shows. 



 Figure (a) 
 The vortex is listed in the bluff body downstream non-symmetrically arranged. Set vortex of the frequency f, measured media to the average flow speed V, the vortex of a welcome stream surface width d, the meter body diameter D, according to Kaman Vortex principle, the following relationship: 

 f = StV, / d formula (1) 
 Where: 
 f-body side of the generated Karman vortex frequency 
 St-Strom Hal number (dimensionless number) 
 The average fluid flow rate of V- 
 d-vortex width of the body 
 Thus, by measuring the separation frequency of Karman vortex street can calculate the instantaneous flow. Among them, the the Strobel the Howl number (St) is a dimensionless unknown. 
 Figure (b) the Strobel the Howl number (St) and Reynolds number (Re). 














 Figure (b) 
 In the curve of the table St. = 0.17 the straight part of the release frequency of the swirl flow rate is proportional to is the vortex flow sensor measuring range degrees. Detect the frequency f can be obtained flow rate of fluid in the tube, the volume flow rate calculated by the velocity V. Measured by the number of pulses and the volume ratio of the amount, called the instrument constant (K), see (2) 
 K = N / Q (1/m3) formula (2) 
 Where: K = instrument constant (1/m3). 
 N = number of pulses 
 Q = volume flow (m3) 
 Three main technical indicators table (a) 
 Nominal diameter (mm) 25,40,50,65,80,100,125,150,200,250,300 (300 ~~ 1000 plug-in) 
 Nominal pressure (MPa) DN25-of DN200 4.0 (> 4.0 agreement supply), DN250-DN300 1.6 (> 1.6 protocol supplier) 
 Piezoelectric medium temperature (℃): -40 ~ 260 -40 ~ 320; capacitive: -40 to 300 -40 to 400 -40 to 450 (protocol order) 
 Body material 1C