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DOCUMENT TITLE
ULTRASONIC FLOWMETER SERIES 6, MODELS Q.SONIC
PLUS
SUBTITLE
QUICK START MANUAL
DOCUMENT NUMBER
22.100.200.000.02/2
REVISION
B
REVISION DATE
2013-02-22
This reproduction is sole property of Elster NV/SA and is subject to the conditions that it or any information contained therein will not be used in any way
detrimental to our interests and that all copies will be returned immediately on demand
PAGE
11 OF 29
22.100.200.000.02_2_B ULTRASONIC FLOWMETER SERIES 6.DOC
Figure 5: SPU compartments
Figure 6: SPU cover
The rear compartment comprises a field terminal board used for connecting the Ultrasonic
Flowmeter Series 6 to the end users applications. For detailed information about this see
chapter 5.2.2.
4.3
Transducers
The ultrasonic signals required for the flow measurement are generated and received by
ultrasonic transducers.
Piezoelectric transducers employ crystals or ceramics that are set into vibration when an
alternating voltage is applied to the piezoelectric element. The vibrating element generates
sound waves in the gas. Since the piezoelectric effect is reversible, the element will
become electrically polarised and produce voltages related to the mechanical strain, when
the crystal is distorted by the action of incident sound waves. Because the acoustic
impedance of the gas is much smaller compared to the acoustic impedance of the
piezoelectric element, and to maximise the acoustic efficiency, a matching layer is
employed between the gas and the piezoelectric element.
The transducers used in the Ultrasonic Flowmeter Series 6 are type ‘NG’, see Figure 7.
Figure 8 visualises the NG transducer with the mounting bracket.
Figure 7: NG transducer
Figure 8: NG transducer with the mounting bracket.
4.4
Flow cell optional pressure sensor
As an optional feature the UFM can be equipped with a pressure sensor. This pressure
sensor is used for: