Protection
Measurement Types
2 - 8
SKF Multilog On-Line System IMx-M
User Manual
Figure 2 - 7.
Example of a Complementary Sensor Graph.
Eccentricity
Eccentricity
is used for measuring the bow of a rotor at slow roll. It measures peak to
peak within the measuring range of 3 to 600 rpm by using displacement sensor.
Gap
The
Gap
measurement and alarming is provided to enable the measurement of the
probe tip to object distance.
It is also possible to configure alarms which among other uses can be used to enable
protection from damage that caused by the shaft coming too close to the sensor and
touching sensor and/or machine.
The Gap measurement is essentially picking out the DC component of the sensor signal.
This measurement value, obtained in volt, can be used to measure the long term/low
frequency displacement/movement of the shaft. To make it useful for protection there
are a set of configurable alarms associated with the Gap measurement.
The Gap alarm levels are configurable in volts, which is also the measurement unit used
for the Gap measurement.
The user should exercise caution when translating Gap distances
into volts.
The Gap alarming can be used in conjunction with Radial shaft vibration or Eccentricity
as a means of protecting the shaft from touching the proximity probe by setting an
alarm if the shaft gets outside the configured alarm levels.
