YSI ADV6600 - Manual (Page 51)

Section 4. Calibration and Diagnostics
ADV6600
Y S I
Environmental
Page 41
With these basic facts in mind, it becomes easier to understand what was observed in the two
laboratory bucket Beam Checks and why the results of the two experiments indicated that the
Doppler sensor was functioning properly.
For the first experiment, the sensor was on the bottom of the bucket and the following display was
observed.
The key to understanding this display is to remember that with the sensor on the bottom of the
bucket, the sampling volume of the sensor was not allowed to function at all. Instead, the acoustic
pulses simply bounced off the plastic surface and returned very quickly to the receivers. It is
possible to note that amplitudes (intensities) of the three signals are approximately equal and this
Sampling Volume
Reflection from bucket
bottom. Low x-axis
value because bottom
is very close to
receiver arms