YSI SonTek ADVField, Technical Documentation Manual

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SonTek/YSI
ADVField Software Manual (September 1, 2001) 21
Section 4. Hardware Diagnostics (ADFCHECK.EXE)
Included with the ADVField software is a diagnostic program (
ADFCHECK.EXE
) that can be used
to verify ADV performance and identify most hardware problems.
ADFCHECK
is the same pro-
gram used at SonTek during system testing. It provides you with a powerful tool for understand-
ing and verifying system performance. We recommend you become familiar with
ADFCHECK
and
use it on a regular basis during data collection. Checking the ADV before every experiment can
identify problems that could cause the loss or corruption of data.
For ideal testing conditions, mount the ADV such that the probe is submerged in water with a
boundary (surface, side, or bottom) within view. Ideally, the boundary should be placed 10-20 cm
beyond the ADV sampling volume.
ADFCHECK
command line syntax is:
ADFCHECK [com port] [output file]
The
[com port]
parameter is the communication port to which the instrument is connected (
1
for COM1,
2
for COM2).
The optional
[output file]
parameter gives the file name to which signal strength profiles will
be written. If no output file is specified,
ADFCHECK
will not record the profile data. The output file
uses a tabular ASCII format with four columns. The first column is the sample location in ADV
timing units. The next three columns are the signal strength (in ADV signal strength counts) for
the three receivers at that location. See ¶4.1 for a description of ADV units.
This program can be run continuously. You do not need to turn off the computer or shut down
the program when replacing probes or connecting cables. Running this program while changing
probes (10-MHz ADV only) is a good way to ensure the probe is properly installed.
See the ADV Principles of Operation for more information about the signal strength profiles.
4.1. Sample Program Output
The ADV sends a pulse of sound, and
ADFCHECK
plots the return signal strength for each of the
three receivers as a function of time following the transmit pulse. The output plot shows several
features: increased signal strength in a bell-shaped curve corresponding to the sampling volume,
a sharp spike from the boundary reflection if within range, and signal leveling to the electronic
noise level. The display is updated every 1-2 seconds and each plot is the average of a number of
samples. Figure 5 shows an example of this output using data from a 10-MHz ADV with a 5-cm
distance to the sampling volume.
The horizontal axis is given in ADV timing units – time corresponds to the distance from the
transmitter where the return signal is generated. One count on the axis corresponds as follows:
5-MHz ADVOcean Probe: 1.2 mm
10-MHz ADV Probe: 0.6 mm
16-MHz MicroADV Probe: 0.375 mm
The vertical axis is given in ADV signal strength units. These are the same units output by the
data conversion program
GETAMP.EXE
. One count for signal strength is equal to 0.43 dB.