EES-101 Series Ultrasonic Flowmeter
Revision: 3.0.1
Page 16 of 65
4.1.4
Z Method
The signal transmitted in a Z method installation has less attenuation than a signal transmitted with the V method
when the pipes are too large, there are some suspended solid in the fluid, or the scaling and liner are too thick .
This is because the Z method utilizes a directly transmitted (rather than reflected) signal which transverses the
liquid only once.
The Z method is able to measure on pipe diameters ranging from 100mm to 800mm (4
〞
~32
〞
) approximately.
Therefore, we recommend the Z method for pipe diameters over 300mm (12
〞
).
4.1.5
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).
4.2
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.
4.2.1
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.
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