HP Data Explorer 4 Series - Manual (Page 191)

Noise Filtering/Smoothing
Data Explorer ™ Software User’s Guide 4-19
4
3. Click OK.
The trace is displayed with an NF, SM, or NR trace
label.
4. To return to the original trace, see “Returning to the
original trace” on page 4-4.
High-resolution data Noise
Removal
(NR)
(Does not
affect peak
resolution.)
Specify the number of standard deviations of
noise to remove. The software automatically
calculates the average white noise for all
frequencies across the spectrum, then
removes the specified number of standard
deviations of noise. This method slightly
affects peak intensity, and removes peaks with
a signal-to-noise ratio less than the specified
standard deviation.
In general:
If you set % White Noise
Std Dev to: removed is:
1 68
2 95
3 99
If applying Noise Removal with a certain Std
Dev does not yield the necessary noise
removal, return to the original trace (see
“Returning to the original trace” on page 4-4)
and apply the Noise Removal again with a
higher Standard Deviation setting. Applying
the Noise Removal more than one time with
the same Standard Deviation setting will not
improve noise removal.
Type of Data
Suggested
Method
Description