Ultraflux Uf 811 CO, User Manual, Page: 58 / 106

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NT UF 811 CO GB (c) / March 2014
3) Deletion rate (CutOff Q)
The deletion rate is the flow rate value below which the flow meter displays 0. This gives us a clear
indication of a flow rate considered to be zero.
4) Product
Drop-down list for choosing the type of product transported in the channel.
5) Delta T0
The deltaT0 field is used to correct installation errors. For example, it is possible to compensate for a bias
due to an incorrect position of the probes by adding to deltaT0 the value required in order to rectify it.
6) Vmin and Vmax
In certain situations, the velocity of the fluid measured by the flow meter may be disrupted. Limits can then
be set for the velocity of the fluid using a minimum velocity and a maximum velocity.
7) Probe immersion depth
For it to be possible for the velocity measured by a chord to be included in the flow calculation, the chord
must be sufficiently submerged so as not to suffer disturbances created by the trough of the wavelets or for
there to be no interference between the direct path of the ultrasonic wave and the path of the wave
reflected by the surface.
If the signal generated by the reflected wave follows the signal generated by the direct wave too closely, the
wanted signal may be appreciably altered by the secondary signal. The minimum immersion depth of the
probes below which the measured velocity is considered invalid must therefore be indicated. This minimum
immersion depends on the frequency used and the length of the acoustic path.
Comment: The immersion depth of the probes is counted from the central plane of a chord.