Xylem SonTek FlowTracker2 - Pre Measurement Diagnostics; Table 7:4 - Pre Measurement Diagnostics

SonTek – a Xylem brand
FlowTracker2 User’s Manual (January 2019)
111
7.3. Pre Measurement Diagnostics
Pre Measurement Diagnostics is an essential step in the measurement process to
ensure accurate and consistent measurement results. The functions evaluated in pre-
measurement diagnostics are the same as discussed in Office Diagnostics.
a) The functions that are evaluated during diagnostic test process are located under
the Utilities menu.
b) The functions that are of key importance during the pre-measurement diagnostic
tests are System Clock, Velocity Data, SNR Data and Beam Check functions.
c) It is recommended that Pre Measurement Diagnostics should be performed
before each measurement is started.
d) To verify the Internal System, Raw Data and Beam Check functions place the
FlowTracker2 probe in moving water well away from any underwater obstacles in
the region of the measurement section.
e) The variables that are evaluated during the diagnostic tests are listed in Table 7:4.
Table 7-4 - Pre Measurement Diagnostics
Function
Verification
System
Clock
• Verify if the internal system clock date and time is correctly set and adjust if
required.
• All data sets recorded during a FlowTracker2 measurement receive a date
and time stamp,
• Date and Time is essential Metadata in the processing and application of
measurement results.
Recorder
• Verify if the available memory is sufficient for performing a measurement,
• Insufficient memory on the recorder could affect the measurement operation
and or recording of measurement file.
Battery Data
• Evaluate the battery voltage and capacity based on the battery type selected,
• Insufficient power supply could affect the measurement operation.
GPS Data
• Evaluate the GPS information received, with the focus on number of satellites,
and HDOP values. This will indicate the level of accuracy of the GPS
measurement.
Raw Data
Display
• The raw data displayed of all variables is updated once per second.
• Velocity, data should appear reasonable for the environment (short term
variations are expected and are most likely real).
• SNR, data should ideally be above 10 (units are dB), but measurements can
be made as low as 3-4 dB.
• Temperature
, data should reasonable to the environment. Temperature data
is used for sound speed calculations and can affect velocity data (see
Principle of Operations).
Automated
Beam Check
• Place the probe in moving water well away from any underwater obstacles;
follow the on screen instructions for the test. Perform Beam Check
measurement as described in
Beam Check Operation.
• Automated Beam Check, review of Automated Beam Check results see
Automated Beam Check,
• Beam Check, review of Beam Check results see Beam Check.
Beam Check