Nortek Vectrino - Mounting Guidelines

NORTEK VECTRINO VELOCIMETER
User Guide
33
Rev. C • 10.2004
Select Sample on sync to have the Vectrino output a sample after every rising
edge of SyncIn. To use this mode, the start on sync mode must be used as well.
Therefore, the fi rst rising edge only starts the averaging process for the fi rst
sample. The fi rst data sample is output on the second rising edge of SyncIn. The
output data at each rising edge of SyncIn will correspond to an average since the
last rising edge of the SyncIn. The Vectrino must be confi gured with the setup
software for a sampling rate that is equal to or higher than the sampling rate that
will be used.
Vertical/Horizontal Velocity Range
This is a theoretical estimate of the actual velocity range along the vertical axis
(along the transmit axis) and in the plane perpendicular to the transmit axis (usu-
ally the horizontal plane).
Analogue Outputs
When analogue output is enabled, the 3D velocity is output as 0–5 V continuous
signal over a separate set of three wires, one for each velocity component. Full
range specifi es the velocity range that will correspond to the full analog output
range.
Mounting Guidelines
The following guidelines should be observed:
•
When mounting the Vectrino near large obstructions (bridges, piers, walls,
etc.), ensure that there are no obstructions between the sensor and the focal
point (sampling volume) located about 5 cm from the transducers. Obstruc-
tions directly behind the sampling volume may corrupt the data.
• Consider the effects of large objects on the fl ow itself. A rough rule of thumb
is that objects disturb the fl ow as far as 10 diameters away from the object.
Flow disturbance is greatest directly downstream in the wake behind the ob-
ject.
• All acoustic transducers must be submerged during data col lection. Operat-
ing with the transducers out of water will not cause damage, but your data
will be meaningless.