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6.4.3
Damping
The CU100 flowmeter has an adaptive filter (damping) to provide stable flow rate and analog
output readings in the presence of continuous flow rate fluctuations.
The configuration of this filter can be very useful in the cases where the flow rate readings
have some instability (due to air bubbles, solids in suspension, etc.).
Only the flow rate indication of the display and the analog output are affected by the filter.
The relay output and the totalizer act according to the instant flow rate. Selecting a filter with
a longer or shorter integration time will provide more or less stable readings and will also affect
the response time to small variations of flow rate.
The integration time is selected in seconds, with a minimum value of 0 and a maximum value
of 100 seconds. For example, with an integration time of 15 seconds, the display will
indicate the flow rate reading of the average flow rate over the last 15 seconds from the last
update of the display. This does not mean that the display is refreshing its data every 15
seconds. The display shows a new value several times per second, indicating an average of
the flow rate values of the last 15 seconds.
When there is a sudden variation of the flow rate then the filter should react as fast as possible
to give a correct reading of the new value. For this, the filter controls the deviation of the
instant flow rate with respect to a reference for each reading. If this deviation exceeds the
established limits, the filter will stop acting, indicating the instant value, and will start again
the filtering process.
6.4.4
Offset
In order to obtain a perfect linearization of the instrument, it is recommended to make an
adjustment of the zero offset each time an installation is performed.
When the option Offset is selected, the following screen is shown:
If the first option to make the correction is chosen, the flow rate must be zero, that is, the
liquid inside the pipe where the transducers are installed should be completely stopped.
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