1.Working Principle:
The vortex flowmeter operates on the basis of Karman vortex street principle. If put a vertical cylinder in flow fluid,during the range of Reynolds number will alternate to form a regular vertex behind the cylinder two sides,named as Karman vortex street.The direction of vortex street is inward,up will form a clockwise rotation,down will form a counter-clockwise rotation,the frequency in single side in proportion to flowrate, in inverse proportion to the diameter of vortex producer,the relationship of them as following:
f=St×v／d
In the formula:St-Jack straw Hal number;f-frequency product by single side vortex;v-flowrate;d-diameter.
Instrument parameters K: a ratio of separation pulse amount of vortex to the volume amount:
K=N／V
In the formula:
K-instrument coefficient (pulse 1/m3)
N-pulse number (time)
V-volume amount
The relationship between the vortex separation frequency and liquid flow is as follows:
f=K×Q
In the formula:
f-frequency (time)
Q-flow （m3/h）
By testing the vortex separation frequency, the liquid flow in the pipe can be measured.

2.Type Selection: