User manual

Section 5: Range, Digits, Rate, Bandwidth, and Filter Series 3700 System Switch/Multimeter Reference Manual
5-10 3700S-901-01 Rev. C / July 2008
Digital filter window
The digital filter uses a "noise" window to control the filter threshold. As long as
the input signal remains within the selected window, A/D conversions continue
to be placed in the stack. If the signal changes to a value outside the window,
the filter resets and starts processing again, starting with a new initial conversion
value from the A/D converter.
The noise window, which is expressed as a percentage of range (or maximum
temperature reading), allows a faster response time to large signal step changes
(for example, scanned readings). A reading conversion outside the plus or
minus noise window fills the filter stack immediately.
If the noise does not exceed the selected window, the reading is based on the
average of the reading conversions. If the noise does exceed the selected
window, the reading is a single reading conversion and new averaging starts
from this point. The noise window for the two filter types are compared in the
filter window below.