User's Manual

Table Of Contents
Option Description
Spectrum - Response Display the spectrum from the response input.
Coherence Describe the degree of linear relationship between the reference
and response inputs. A coherence value close to one (1.0) at a
frequency indicates the response and reference are linearly
related, and the measurement signal to noise ratio is high.
Cross Channel Phase
(Resp/Ref)
Display the phase relationship of the response and reference
signals.
FRF (Ref/Resp) Display a spectrum representing the transfer function of the
reference input/the response input. It is the amount of force that
is required to provide a response at a given frequency.
FRF (Resp/Ref) Display a spectrum representing the transfer function of the
response input/the reference input. It is the measured ratio of
response of the structure acceleration to a known excitation.
5. Press F6 Plot Format F12 Plot Format or to set the display for multiple plots.
6.
Press Enter.
8.6 Set up the job
8.6.1 Set the measurement parameters
1. From the ODS/Modal main menu, press F8 Job Manager.
2. Use the up and down arrow keys to select a job.
3. Press F4 Edit This Job > F4 Set Meas Params.
4. Set the following options as necessary.
Option Description
F2 Set Number of
Points
Enter a number between 1 and 1,024. The number of measurement point
directions and number of points determine the total number of locations
to collect data. For example, if the measurement direction is XYZ and
1,024 points are defined, a total of 3,072 locations (1,024 X, 1,024 Y and
1,024 Z) are available in the job. The default is 20.
F3 Set Starting
Point
Enter a number between 1 and 9,998 to set the first measurement point
to display when you collect data. If a job has 20 measurement points, the
starting point could be from 1 through 9,979. If the starting point is
9,979, the second point number would be 9,980. The default is 1.
ODS/Modal
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DRAFT