Xylem SonTek FlowTracker2 - 3.4.3 Quality Control Settings; 3.4.3.1 SNR Threshold

SonTek – a Xylem brand
FlowTracker2 User’s Manual (January 2019)
47
Quality Control Settings screen includes the
following parameters,
a) SNR Threshold,
b) Std Error Threshold,
c) Spike Threshold,
d) Velocity Angle for Warning,
e) Tilt Angle Warning.
f) To select a parameter,
i). Use up or down scroll arrows keys to select a
parameter,
ii). The parameter selected will be highlighted in
yellow.
g) To navigate to Template Menu,
i). Press the Left Soft Key.
Figure 3:13 - Quality Control
Settings
Properties associated with the parameters in quality control settings are defined in
Table 3:9,
Table 3-9 - Quality Control Settings - Properties
Parameter
Min
Max
Default
Units
Required
SNR Threshold
0
50
10
dB
Yes
Std Error Threshold
0.001
0.25
0.01
m/s or ft/s
Yes
Spike Threshold
0.01
50
10
%
Yes
Velocity Angle for Warning
0.1
90
20
degrees
Yes
Tilt Angle Warning
0.1
5
5
degrees
Yes
SNR Threshold 3.4.3.1
The SNR Threshold parameter is a minimum threshold placed on the SNR variable
during real-time data collection.
a) SNR is primarily a function of the amount of particulate matter in the water. For
good conditions, SNR should be at least 10 dB.
b) The system can operate effectively with SNR as low as 2-3 dB, although the noise
in individual velocity measurements will increase.
c) The default SNR Threshold applied in FlowTracker2 is 10dB.
d) To change the SNR Threshold,
i). Use the backspace key to clear current entry,
ii). Type in the new value using the keypad.
e) To DISABLE the SNR Threshold,
i). Use the backspace key to clear current entry until “Disabled” is displayed.