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Reference, Installation, and Operations Manual
Section 6: Meter operation
3-9000-743 Rev S
June 2013
Measurement
181
61
Section 6: Meter operation
The purpose of this section is to instruct the user on the operation of the 3410 Series Ultrasonic
Flow Meters meter, particularly for features not discussed in Section 5. It is assumed, in this
section, that the user is familiar with basic ultrasonic metering.
Flow Meters meter, particularly for features not discussed in Section 5. It is assumed, in this
section, that the user is familiar with basic ultrasonic metering.
6.1
Measurement
The Ultrasonic Gas Flow Meter precisely measures the transit time of an ultrasonic wave passing
through the gas to determine the mean axial velocity of the gas through the unit. The
measurement paths (also referred to as “chords”) are angled to the pipe axis, and each chord
has two transducers acting alternately as transmitter and receiver as shown in
through the gas to determine the mean axial velocity of the gas through the unit. The
measurement paths (also referred to as “chords”) are angled to the pipe axis, and each chord
has two transducers acting alternately as transmitter and receiver as shown in
(for
SeniorSonic
TM
(for JuniorSonic
TM
meters). This permits the transit times
to be measured both with and against the flow.
The transducers are mounted on the meter body at accurately known locations for each pipe
size so the distance L between opposing transducers and the angle are precisely defined for the
measurement path.
size so the distance L between opposing transducers and the angle are precisely defined for the
measurement path.
Figure 6-1 SeniorSonic measurement principle