Page 16 - GuardII+ Series 4208 Platform Flux User Manual

GuardII+ Flux Card Operation

• Measurements will be stored every 30 minutes until 100 measurements have been
saved; this occurs at 11:30 a.m. on Wednesday. Now, measurements will be saved
daily.

• The first successful measurement on Thursday occurs at 12:00 a.m.; this one is saved,
and another measurement won’t be saved until at least Friday at 12:00 a.m. However,
the machine is shut down at 1:15 a.m., so no measurements will be possible until the
machine is started up again.
• The machine is started up at 5:50 p.m. on Friday, so the first successful measurement
on Friday will be at 6:00 p.m. and it will be saved in the Archive.
• On Saturday at 12:00 a.m., the machine is running, so the first successful
measurement will be at 12:00 a.m. and it will be saved in the Archive.
• At 8:20 Saturday morning the flux data is downloaded.
• The next measurement occurs at 8:30 a.m. Since the data was just downloaded, this
measurement and the next 99 measurements will all be saved; this occurs at 11:00 on
Monday. Now the data collection reverts to once per day, with the next measurement
being saved at 12:00 a.m. on Tuesday, if the machine is still running.

4.5.3. Round Rotor Archive

The round rotor Archive uses a generator load point detection scheme for the structure of
the Archive. The Archive is stored as a matrix of ‘bins’, each corresponding to a load point
and there are a number of load points equal to the number of coils on the machine plus one
for measurements that could not be analyzed. For example, for a GuardII+ installed on a 10-
coil per pole machine, the Flux-R Archive will have 11 load bins; one for measurement results
that correspond to each coil, plus one for measurements that could not be analyzed.
Determining the appropriate load bin for a measurement is based on a calculation of the
Quality Value. The Quality Value (QV) indicates the quality of the flux measurement result for
a particular coil; while shorts can be detected at any load, the shorted turn detection is most
accurate when the QV for that coil is at 0.98 or higher. When a measurement is taken, the
QV for every coil is calculated; whichever coil has a QV of 0.98 or higher, the measurement
is saved in the load bin for that coil.

NOTE:
If a measurement result does not have a Quality Value higher than 0.98
for any coil, that measurement will not be Archived.

NOTE:
The extra Archive bin is reserved for measurements that have a good
signal amplitude, but the flux peak-picking algorithms could not find the
correct peaks to analyze.

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