Nortek Vectrino - Pressure (Vector); Noise Floor

Service Manual 67
© 2018 Nortek AS
180, 270 and then 360/0 - corresponding to North, East, South and West respectively)
Click Stop Data Collection, invert instrument, click Start Data Collection and repeat the procedure.
Figure: Rotate
the instrum ent
to verofy
com pass
functionality.
Clockw ise is
positive
Remember to perform a Compass Calibration before deployment, to account for magnetic
interference near the instrument.
3.1.2.4 Pressure (Vector)
To test the pressure sensor:
1) Set the pressure sensor depth to 0.2 m in the On-line > Set Pressure Offset dialog.
2) Place the instrument in a suitable container filled with water (approximately 0.5 m deep)
3) Verify that the pressure reading is correct; with the instrument submerged to 0.5 m, and with an
offset of 0.2 m, the pressure sensor should read 0.7 m.
An alternative way to test whether the sensor is functioning is by forming a seal around the sensor
with your mouth and blowing to observe an increase in pressure.
Have in mind that the pressure sensor is not a depth meter. Due to atmospheric pressure variations,
the sensor signal may have an offset. Therefore, remember to set a Pressure offset before every
deployment.
3.1.3 Noise floor
First, check the noise level of the instrument. See the readings in the software, under the Current
tab. Pinging in air should produce signal strengths (amplitudes) of
45-55 counts for Vector
50 counts for the Vectrino and the Vectrino Profiler
When the instrument pings in air, the velocity measurements will be the noise floor. The signal
values above are therefore referred to as the noise floors. Data from all beams should show a similar
noise floor. Note: Background noise is very prone to interference from nearby sources, such as a
power supply. During testing make sure the instrument is far enough away from other electronics.
Put the instrument in a bucket of water and observe the signal strength and the velocity. The signal
strength should rise noticeably (the actual level depends on the size, shape and material of the
bucket), and the velocity data should appear less noisy. If the velocity graphs remain weak even with
the probe in water, try varying the position of the probe or add some seeding to the water in the form