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W
R
X
S
AVE
UNNER
I
7. Choose whether to Truncate
8. Touch the Suppress DC checkbox if you want to make the DC bin go to zero. Otherwise, leave it unchecked.
9. Touch inside the Output type field, and make a selection from the pop-up menu.
the Window field, select a window type.
10. Touch inside
11. Touch inside the Algorithm field and select either Least P
ANALYSIS
Pass/Fail Testing
Comparing Parameters
Each Pass/Fail input (Qx) can compare a different parameter result to a user-defined limit (or statistical range)
under a different condition.
The conditions are represented by these comparison operators:
At the touch of a button, test results can also be compared to these standard statistical limits:
•
current mean
•
mean + 1 SD
•
mean + 3 SD
1
When the FFT transform size does not match the record length, you can truncate the record and perform an FFT on the shorter record. T
will increase the resolution bandwidth.
2
Zero-fill is useful wh
en the source data for the FFT comes from a math operation that shortens the record. This is commonly encountered in
filtering operations like enhanced resolution. The missing data points are replaced by data values, whose am
between the last data point and the first data point in the record. This guarantees that there is not a first-orde
Since the data at the end of the record is "filled" data, it is advisable to select a weighting window other than rectangular
of the fill on the resulting spectrum.
3
The default algorithm is a l
east primes algorithm that computes FFTs on transform sizes having lengths that can be expressed as factors of
N
K
2
*5
. This is very compatible with the record lengths encountered in the oscilloscope, which are often multiples of 1, 2, 4,
of 2 The other choice is a power of two algorithm where the record lengths are in the form of 2
than the least primes algorithm. The price that is paid is a record length that is not the same as the acquired signal. The power-of-two FFT
N
uses the first 2
points of the record. For example, if you acquire 500 points in your trace, the power-of-two FFT would only use the first 256
points.
142
ERIES
1
or Zero-fill
2
the trace display.
3
rime
from the pop-up menu.
N
. The power of 2 algorithm
plitudes are interpolated to fit
r discontinuity in the filled data.
to minimize the effect
5, or 10. or Power
generally runs faster
WRXi-OM-E Rev C
his
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