Gen II
User Manual
13-5 – Transient Vibration Survey
Chapter 13
Revision 4.10, Apr 20
13.1.1.1.4.
Use the [
] key to move to the maximum frequency field, immediately to the right of the
word “to” and the minimum frequency field. Use the analyzer keypad to enter the
highest frequency of interest for this survey relative to the frequency units selected in
paragraph 13.1.1.1.2 above. You should also consider other factors such as Harmonics. If
you want multiples of the fundamental frequency included in the frequency range,
determine to what extent that need is (1X, 2X, 3X, and so on) then extend the frequency
range to include it. For example, 300Hz is the frequency of interest, the fundamental
frequency. If you want 3X harmonics included in the frequency range you must multiply
the fundamental frequency (300 Hz) X the harmonic range (3X) and arrive at an upper
range of 900 Hz.
13.1.1.1.5.
Use the [
] key to move to the “
Res. Lines:
” field. Resolution is the number of lines of
resolution for the spectra display. Press the [
] key to increase the number of lines up to
3200. Normally 400 to 800 lines are sufficient for spectra. Higher resolutions may be
used when separation of two frequencies of very close proximity is required.
13.1.1.1.6.
The RPM/Line (Hz/Line) field is an informational entry. The frequency unit displayed is
determined by the entry in paragraph 13.1.1.1.2. It will tell you the approximate interval
between each line of resolution and the next. This is based on the minimum and
maximum frequencies selected in paragraphs 13.1.1.1.3 and 13.1.1.1.4 and the Res. Lines
entry selected in paragraph 13.1.1.1.5. This can be helpful if you are trying to separate
one single peak into two very close peaks. The value displayed will be the frequency
interval between each pair of lines on the final spectral display.
13.1.1.1.7.
Use the [
] key to move to the “
Display
” field. Use the [
] key to select the Display
type. Your selection in this field will determine how the initial data is displayed on the
analyzer screen during acquisition. A selection of “Overall” will provide a numeric value
reading while a selection of “Spectra” will display a full spectral graph of the acquired
data. Either selection will cause the analyzer to begin recording data as soon as the data
acquisition process begins. It should be noted that a setting of “Overall” in this field will
provide faster data updates and a higher accuracy due to the lower demand on the digital
signal processors for this type of display. The display can be toggled between the two
during the job. See paragraph 13.1.8 for instructions on switching between the two
display modes. The data can then be review or played back after recorded in full spectral
or waterfall modes. The selection of “Overall w/Record” or “Spectra w/Record” allows
the user to begin the data acquisition process, view the data and confirm the values then
select the point at which data will begin to get recorded.
13.1.1.1.8.
Use the [
] key to move to the “
Every
” field. Enter a sample rate in numbers of samples
per millisecond. The sample rate determines how often the analyzer acquires the data. A
setting of “0” tells the analyzer to update as rapidly as possible for existing conditions. A
setting 1000 tells the analyzer to sample once every second. If you are acquiring a
“startup” survey, where the engine acceleration is automatic and very rapid, you may
wish to set the rate at shorter intervals, 50 or 20 for instance. If you can control the
