GE AquaTrans AT600, Руководство пользователя

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AquaTrans™ AT600 User’s Manual 7
Chapter 1. General Installation Instructions
1.7 Choosing a Clamp-On Fixture/Transducer Location
For a given fluid and pipe, the accuracy of AT600 depends on the location and alignment of the transducers.
In addition to accessibility, when choosing a transducer location, follow these guidelines:
•
Position the clamp-on fixture(s) and transducer system so that there are at least 10 pipe diameters of
straight, undisturbed flow upstream and 5 pipe diameters of straight, undisturbed flow downstream
from the measurement point (see
Figure 7 below). Undisturbed flow means avoiding sources of
turbulence in the fluid such as valves, flanges, expansion joints, elbows, swirl, and cavitation.
Figure 7: AT600 Clamp-On Fixture/Transducer Location
•
Locate the transducers on a common axial plane along the pipe (see Figure 8 below). The transducers
should be mounted on the side of the pipe, rather than the top or bottom, because the top of the pipe
tends to accumulate gases and the bottom tends to accumulate sediment. Either condition may cause
excessive attenuation of the ultrasonic signal. There is no similar restriction with vertical pipes, as
long as the flow direction is upward to prevent free falling of the fluid in a partially filled pipe.
Figure 8: Good and Bad Transducer Locations
Flow Direction
D
DOWNSTREAM
UPSTREAM
10 X D (in.)
5 X D (min)
Good
Good
Good
Bad
Bad
Flow
Flow
Flow