5-8
Chadwick-Helmuth Company, Inc.
Chapter 5
- Balance Measurement and Solutions
5.3.2 Frequency Units
The balance frequency may be displayed in either revolutions per minute (RPM) or cycles per second
(Hertz). Use the
<CHANGE>
soft key to convert the frequency from one form to the other. Once this
parameter is set, all other displays of frequency data are made in these units. The default is RPM. This
parameter is not overridden when a balance chart is selected.
5.3.3 Balance Multiplier
The balance multiplier factor is an integer value by which the balance frequency is multiplied before a
balance measurement is taken. It is typically used to analyze
n
-per-revolution vibration signals that
may be present in the spectrum. The default value i s1 (one per revolution). For example, a balanc
frequency of 300RPM and a balance multipl ier of2 causes the 8500C/C+ to acquire a balanc
measurement at the two-per-revolution frequency (600RPM). Set the balance multiplier by entering
the desired value from the numeric keypad.
5.3.4 Balance Type
Balance type describes the particular system used to measure the phase of the vibration signal. Th
8500C/C+ currently supports the following balance type settings:
•
Photocell
(Photocell System)
•
Mag pickup
(Mode l3030 Magnetic Pickup)
•
Strobex
(Model 135M-12 Strobex Tracker)
The Photocell and the Strobex are optional with the 8500C/C+ kit. The magnetic pickup can be
purchased separately. Use the
<CHANGE>
soft key to toggle between them. Note that when a balance
chart is selected, the current balance type is automatically overridden with the type stored in the chart.
5.3.5 Auto/Manual Stop
If a Photocell or magnetic pickup balance is being performed, the 8500C/C+ can be directed to
automatically terminate balance data acquisition when a satisfactory measurement has been obtained
(auto-stop mode). Manual stop mode, on the other hand, requires you to press the
STOP
key to end th
measurement. Note that if you use the manual stop mode, the 8500C/C+ must have a satisfactory
average of balance data points before it can accept the measurement as valid. Use the
<CHANGE>
soft
key to toggle between the two modes. The default mode is auto-stop.
5.3.6 Angle Units
The phase angle is a measure of the phase of the velocimeter signal relative to a fixed reference point
on the rotor system. It corresponds to the central angle subtended by the two vectors, and is given
either by the position of a reflective target illuminated with the Strobex, or through the phase meter
display on the 8500C/C+ liquid-crystal display (LCD).
Phase angle units may be displayed in either degrees or clock angle units. Use the
<CHANGE>
soft key
to convert the units from one form to the other. Once this parameter is set, all other displays of phase
measurement data are made in these units. This parameter is not overridden when a balance chart is
selected.
To Next Page
Loading...
Need help?
General
