Section 4 — Measurement Types and their Uses
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The table includes typical bandwidth recommendations that may be
made by your instrument, based on the default machine speed:
Demod Bandwidth Recommended Speed Range
250 Hz - 10 kHz <100 RPM
500 Hz - 10 kHz 100 - 300 RPM
1 kHz - 10 kHz 300 - 1000 RPM
2 kHz - 10 kHz 1000 - 3000 RPM
4 kHz - 10 kHz >3000 RPM
To view the full range of available bandwidths on the instrument, select
Show Complete List at the bottom of the bandwidth selection list.
If a default machine speed has NOT been configured, your instrument
will NOT be able to recommend a bandwidth. You will need to manually
select a bandwidth option suitable for the application. In this case, you
can use the following steps to determine an appropriate bandwidth:
1. Press Measure > Press Spectrum Waveform to take a
quick snapshot spectrum measurement.
2. Press to create a new parameter set > Set the store units to
Acceleration and the Fmax to 20 000 Hz (1200 kCPM).
3. Press to start measuring.
4. Examine the chart for a region of broadband high frequency noise
(haystack).
5. When you set up your demodulation measurement, select a
bandwidth that includes the haystack but excludes any large
individual peaks.
IMPORTANT! It is very important that all the large-amplitude/low-
frequency peaks are rejected. If no significant haystacks are
displayed, we recommend a standard bandwidth of 2 - 10 kHz
(120 - 600 kCPM). Proceed with the demodulation measurement
when you have determined an appropriate bandwidth.
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