EMCO Enterprises Automobile Parts 5707070-A 사용자 설명서
5707070-A
Installation and Operation
2-7
Sono-Trak™ Doppler Ultrasonic Flow Meter
Figure 2-1. Straight run examples
TRANSDUCER PLACEMENT
You should always avoid measuring liquids in vertical downward flows with any flow
meter. In the case of Doppler flow meters, vertical downward flows cause erroneous
readings by introducing air bubbles. Excessive air bubbles attenuate the measurement
signal by hampering penetration of the ultrasonic beam into the fluid. Bubbles will
tend to rise against the flow, and since the Doppler flow meter is capable of totalizing
in both directions, this will cause erroneous flow measurements as the meter factors in
the backward flow of the bubbles. Additionally, in vertical flows it may be difficult to
keep the pipe full, allowing pockets of air into the pipe. This will drastically reduce
the transducer’s ability to penetrate the flow and produce a readable signal.
meter. In the case of Doppler flow meters, vertical downward flows cause erroneous
readings by introducing air bubbles. Excessive air bubbles attenuate the measurement
signal by hampering penetration of the ultrasonic beam into the fluid. Bubbles will
tend to rise against the flow, and since the Doppler flow meter is capable of totalizing
in both directions, this will cause erroneous flow measurements as the meter factors in
the backward flow of the bubbles. Additionally, in vertical flows it may be difficult to
keep the pipe full, allowing pockets of air into the pipe. This will drastically reduce
the transducer’s ability to penetrate the flow and produce a readable signal.
D = Nominal pipe diameter