Baker Hughes Panametrics PanaFlow Z3, Руководство пользователя, Страница: 14 / 118

Chapter 1. Introduction
2 PanaFlow Z3 User’s Manual
1.2 Theory of Operation
1.2.1 Transit-Time Flow Measurement
In this method, two transducers serve as both ultrasonic signal generators and receivers. They are in acoustic
communication with each other, meaning the second transducer can receive ultrasonic signals transmitted by the
first transducer and vice versa.
In operation, each transducer functions as a transmitter, generating a certain number of acoustic pulses, and then
as a receiver for an identical number of pulses. The time interval between transmission and reception of the
ultrasonic signals is measured in both directions. When the liquid in the pipe is not flowing, the transit time
downstream equals the transit time upstream. When the liquid is flowing, the transit time downstream is less than
the transit time upstream.
The difference between the downstream and upstream transit times is proportional to the velocity of the flowing
liquid, and its sign indicates the direction of flow.
Figure 1: Transducer Paths Across Flow Direction
1.3 System Components
1.3.1 Local Transmitter Configuration
The PanaFlow Z3 consists of the new XMT1000 electronics, a magnetic wand, the LX transducer system, and a meter
body as shown in
Figure 2 .
Note:
Actual design varies slightly with size.