Measurement Computing eZ-Record rev.2.1 - Manual (Page 21)

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January 2001 eZ-Record Manual
close to zero. Exponential can be used with all transient excitation methods
in order to force the signals to decay close to zero, (See Response Decay
Percent,) even if the block length is not sufficient to capture all of the
naturally occurring response. If the data decays naturally to a low
amplitude within the block, so that leakage is not significant, exponential
windowing can improve the signal-to-noise ratio by giving reduced weight
to the very low-amplitude data at the end of the block.
Response Decay Percent: The Response Decay Percent is used when an
Exponential Window is applied to the Response Channel. It is the rate of
decay from the first to the last block value.
Miscellaneous Tab - FFT Window (Reference) Panel
The FFT Reference Window is applied to the output (force) of a transducer to
avoid collecting extraneous signals caused by an excitation device, such as an
impulse hammer.
When Rectangular is selected, specify the Start and End of the rectangle as a
percentage of the Frame Period.
When Cosine Taper is selected, specify the Start, End, and Taper of the Cosine
Taper as a percentage of the Frame Period.
Start: This is the percent of the Frame Period at which the Rectangular and
Cosine Taper Windowing functions start.
Stop: This is the percent of the Frame Period at which the Rectangular and
Cosine Tape Windowing functions stop.
Edge: This is the percent of the Frame Period during which the Cosine Taper
Windowing function tapers up and down.
Miscellaneous Tab - Octave Panel
Weighting: No weighting, A B or C Weighting
Filter: Analog or Digital
Miscellaneous Tab - Integration Panel
Differentiation/Integration: g’s-ips-mils, g’s-ips-in, g’s-fps-ft, ips^2-ips-in,
ips^2-ips-ft, fps^2-fps-ft, g’s-mmps-micr, g’s-mmps-mm, g’s-cmps-cm,
mmps^2-mmps-mm, cmps^2-cmps-cm, mps^2-mps-m
Miscellaneous Tab - Low Frequency Cutoff Panel
Low frequency cutoff is used to remove the low frequency effects of integration.
All data point below the value specified are set to zero.
Single: Enter a value for the cutoff amount for single integration.
Double (Hz): Enter a value for the cutoff amount for double integration .