EES-401 Series Ultrasonic Energy Meter
Revision: 3.0.1
Page 17 of 90
4.3.3
N Method (not commonly used)
With the N method, the sound waves traverse the fluid three times and bounce twice off the pipe walls. It is
suitable for small pipe diameter measurement. The measurement accuracy can be improved by extending the
transit distance with the N method ( uncommonly used ).
4.4
Transducer Mounting Inspection
Check to see if the transducer is installed properly and if there is an accurate and strong enough ultrasonic signal
to ensure proper operation and high reliability of the transducer. It can be confirmed by checking the detected
signal strength, total transit time, delta time as well as transit time ratio.
The "mounting" condition directly influences the flow value accuracy and system long-time running reliability. In
most instances, only apply a wide band of sonic coupling compound lengthwise on the face of the transducer and
stick it to the outside pipe wall to get good measurement results. However, the following inspections still need to
be carried out in order to ensure the high reliability of the measurement and long-term operation of the instrument.
4.4.1
Signal Strength
Signal strength (displayed in Window M90) indicates a detected strength of the signal both from upstream and
downstream directions. The relevant signal strength is indicated by numbers from 00.0 ~ 99.9. 00.0 represents no
signal detected while 99.9 represents maximum signal strength. Normally, the stronger the signal strength
detected, the longer the operation of the instrument reliably, as well as the more stable the measurement value
obtained.
Adjust the transducer to the best position and check to ensure that enough sonic coupling compound is applied
adequately during installation in order to obtain the maximum signal strength.
System normally requires signal strength over 60.0, which is detected from both upstream and downstream
directions. If the signal strength detected is too low, the transducer installation position and the transducer
mounting spacing should be re-adjusted and the pipe should be re-inspected. If necessary, change the mounting
method to be Z method.
4.4.2
Signal Quality (Q value)
Q value is short for Signal Quality (displayed in Window M90). It indicates the level of the signal detected. Q
value is indicated by numbers from 00 ~ 99. 00 represents the minimum signal detected while 99 represent the
maximum. Normally, the transducer position should be adjusted repeatedly and coupling compound application
should be checked frequently until the signal quality detected is as strong as possible.
Downstream Transducer
Upstream Transducer
Flow
Transducer Spacing
Flow
Side View
Top View
Section
Pipe Strap
Transducer
Downstream Transducer
Upstream Transducer
Flow
Transducer Spacing
Flow
Side View
Top View
Section
Pipe Strap
Transducer