Lugb Vortex Air Flow Meter with RS485 / 4 -20mA / Pulse
The series of Vortex Flowmeter is based on Von Karman’s Vortex
Principle, which adopts piezoelectric crystal as testing
components. It is a new kind of stress detecting vortex flow
meter.It has the advantages of wide range rate, high accuracy,low
pressure loss, good medium generality, pulse signal output
proportional to flow, convenient to connect with computer etc.As
the detector probe of sensor and the vortex generating body are
installed separately, and the high temperature resistant
piezoelectric crystal does’t contact with medium, so the instrument
is of simple structure, good generality, and high stability.
Vortex flowmeters measure flow rate by detecting the
frequency at which alternating vortices are shed from a bluff
body inserted into the flow stream. This principle of
measurement is known as Von Karman’s vortex street
principle: alternating vortices form behind an object in a
stream(Show in the picture).When d/D=0.28,released vortices
are stable(D is diameter of the pipe).Vortex shedding
frequency are related to width of the bluff body and flow
velocity,formula as bellowed:
f = vortex shedding frequency [Hz]
St = Coefficient(Strouhal number)
V = flow velocity [m/s]
d = width of the bluff body [m]
Strouhal Number is a very important coefficient in vortex
flowmeter, within the range from Reynolds number, Strouhal
Number is close to a constant. As showing in the followed
chart,St=0.17,vortex shedding frequency is proportional to the
flow velocity,from f can be calculated V,the flow range can be
calculated by V.
LUGB series Vortex flow meter is a stress type flow meter,
the released frequency from sensor is detected by the internal
piezoelectric element through sensor(probe).
Measuring medium: Steam,gas, liquid(Avoid of multipledirection
Repeatability:Liquid 0.33% Gas:0.5%
Working pressure:Standard 1.6MPa,2.5~4.0 MPa (on request)
Fluid temperature:-40℃~250℃(Common type)；100℃~
Body material:304 stainless steel(SS316 is optional)
Output signal:Pulse(three wires,low level≤1V;High level≧4V);
Power supply:24VDC(12VDC),Lithium battery
Ambient temperature : -35 ℃ ~ 60 ℃ ( without LCD );
●The structure of Vortex flow meter is simple and strong, no
movable parts,and it is very stable.
●Simple installation and easy maintenance
●Wide measuring rang,the ratio is up to 10:1.
●Low pressure loss and operating costs.
●When measuring the volume of fluid,compensate as
required,replace parts without re-calibrate the flow meter.