Pag. 17 of 52
- Installation
4) Proceed to the electrical connection
7.7 Installation check-up
The signal reception power and quality (
Q
) can be checked through the installation check-up and it’s possible to make
the comparison of the measured flight time by the measuring range depending on the pipe diameter.
7.7.1 -
Signal reception power - M90
The signal reception power, displayed to the menu
M90
with
UP
and
DN
, is indicated by a three-digit number.
[00.0] means missing signal and [99.9] indicates the maximum measurable value.
Although the instrument is working properly with a signal power between 50.0 and 99.9, it is always recommended
to try to get a value as high as possible using the following methods:
(1) Select the most favorable installation position.
(2) Clean the pipe outer surface and apply more coupler grease.
(3) Move the transducers both vertically and horizontally while the signal reception control.
Mechanically lock the transducers when the detected power has reached its maximum value (always checking
that the distance between the two transducers is equal to that indicated in the menu
M25
)
7.7.2 - Signal quality (Q) - M90
Better the signal quality (
Q
value higher), better will be the ‘SNR and consequently the accuracy. In normal operating
conditions the
Q
value, displayed to the menu
M90
, is between 60 and 90. In the case of a lower value, check:
(1) Any interference with other instruments.
(2) The transducers coupling with the pipe surface ube (clean the pipe or add more coupler grease)
(3) The mounting position on the pipe
7.7.3 - Total transit time and Delta Time - M93
The numbers shown in the
M93
are called total transit time and delta time. These values are fundamental to calculate
the flow rate inside the pipe.
The total transit time should remain stable or in any case subject to minimal variations.
If the delta time fluctuates above 20% means that there are problems with the transducers installation.
Fig. 32
3) the inclined surfaces of the ultrasonic transducer
signal emitter (1 in figura 27) should be directed
towards each other
Fig. 31-a
