Measurement Computing eZ-TOMAS rev.11.0 - Manual (Page 31)

Note: Filter Panels apply to ZonicBook/618E and WBK18 channels. Filter Panel functionality does not apply
to WaveBook direct channels or to Medallion channels.
High Pass Coupling Filter (Hz)
High Pass Filter (AC Coupling): When AC Coupling is selected in
the Input Channels tab, the associated input signals will pass through
a 0.1 Hz or a 1 Hz High Pass Filter, depending on which radio button
is selected.
High Pass Display Filter (Hz)
Allows you to eliminate the lower frequencies from the full frequency
range for “no,” “single,” and “double” integrations by entering the
desired cutoff value in Hz. All data points that exist below the
specified value are set to zero.
Integration Units
Accelerometer and Velocity signals can be integrated. Select the
desired integration value (g’s/ips/mils, g’s/ips/in, or g’s/mmps/mm).
Points to note:
(1) If the signal is acceleration, then
(a) single integration results in velocity, and
(b) double integration results in displacement.
(2) If the signal is velocity, then single integration results in
displacement.
(3) The type of integration (none, single, or double) is selected in the
Input Channels tab.
Terms and factors related to the Acquisition Panel
Nyquist Factor In eZ-TOMAS waveform frequency is multiplied by a nyquist factor of 2.56. This
ensures that a sampled analog signal is accurately reconstructed. The 2.56 nyquist
factor is the most efficient in FFT Analysis.
Sampling Rate
A rate that is 2.56 times the Analysis Frequency. If the Analysis Frequency was
1000 Hz and if the Spectral Lines was 800 lines; then the Sampling Rate would be
2560 samples per second. This rate would apply to each channel. Derived from:
Analysis Frequency x 2.56 = 1000 x 2.56 = 2560.
Spectral
Resolution
A value related to Analysis Frequency and Spectral Lines. Where Spectral
Resolution equals the Analysis Frequency divided by 2.56. If the Analysis Frequency
was 1000 Hz and if the Spectral Lines was 800 lines; then the Spectral Resolution
would be 1.25 Hz per spectral line.
Derived from:
Analysis Frequency divided by Spectral Lines = 1000 Hz / 800 = 1.25 Hz
eZ-TOMAS 947394 Edit Menu 4-3