Adding this package enables the user to change the number of gates at which the velocity is computed, and to place the gates anywhere in the measuring range. Therefore it is also possible to change the position of the first measuring gate, if for instance the velocities close to the transducer are not of interest or are simply not measurable (gates outside the flow region).

The functioning parameters that can be tuned when this package is installed are the following:

• Number of gates: up to 1000 gates can be used and placed along the ultrasonic beam axis.
• Starting depth: which defines the position of first measuring gates. It is the distance between the surface of the transducer and the first gate. Defined in mm.

Without this package you will get ...	This package allows you to get ...

When a high resolution is desired over a large depth of measurement, one has to increase the absolute number of measuring points or gates.

Another case where this option package is useful is when the volume to be investigated goes so deep that even with a coarse resolution, the measurement cannot be done at the end of the volume to be measured
When the transducer has to be placed quite far away from the beginning of the volume to be investigated, using this package allows to remove irrelevant information from the gates where no flow exist, thus saving memory for the useful information.