SonTek/YSI
ADVField Software Manual (September 1, 2001) 24
Included with each ADV is a calibration sheet that shows the results from the factory calibration.
One portion of this sheet includes values for noise level, peak level, and peak position during the
factory calibration. The values for noise level and peak position should match those shown on the
calibration sheet to within about five counts.
4.2. Diagnosing Hardware Problems
ADFCHECK
can be used to detect almost any problem that can occur with an ADV. This section
describes the program output for some of the most common situations. When appropriate, figures
showing the program output are included.
Case A: Signal conditioning module not connected
If the high-frequency probe cable is not connected to the ADV processing module, the program
shows zero signal strength across the entire profile for all three receivers. This appears as a blank
graph in
ADFCHECK
, although there may be some noise at low signal strengths (less than 30
counts). This can also occur if the high-frequency cable has been damaged.
Case B: Probe not connected
This situation can occur after changing probes (for 10-MHz ADV probes only) and appears as a
flat response in all receivers after the initial transmit pulse ringing (no change for the sampling
volume or boundary reflection). The signal strength in the flat area will be 10-15 counts lower
than the normal noise level. We recommend running
ADFCHECK
while replacing probes, to be cer-
tain the probe is properly connected. Be aware that this situation can be confused with a faulty
transmitter (case D).
Case C: Weak scattering (Figure 6)
If there is insufficient scattering material (i.e.; very clear, quite water), the peak normally seen
around the sampling volume will be small or non-existent. This situation can be confused with a
malfunctioning transmitter (case D) unless the bottom is in view of the probe.
Case D: Malfunctioning receiver(s) (Figure 7)
The signal from each receiver should have about the same strength as the sampling volume. If the
differences exceed 10-20 counts, clean off the each transducer and make sure the beams are not
physically blocked before calling the factory.
Case E: Malfunctioning transmitter (Figure 8)
This appears as a flat response with signal strength at the normal noise level. This can be con-
fused with a disconnected probe (case A) or weak scattering (case C). Note the absence of a
boundary reflection to distinguish this from Case C.
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