RPM
d
The SPM HD measuring technique
The SPM HD measuring technique is a refinement of the original dBm/dBc measuring technique (see
page D:18), which has been successfully applied for more than 40 years. It is well suited for industrial
condition monitoring, because it works with few, easy to understand in- and output data and with
‘reasonable accuracy’.
Even on a logarithmic scale, there is normally a large, distinct difference between the maximum values
from good and bad bearings. Thus, minor inaccuracies in the input data (rpm and shaft diameter) have
little effect on the evaluated measuring result.
Lubrication condition is indicated by the delta value, i.e. the difference between HDm and HDc.
High readings and a small delta value indicate poor lubrication or dry running. This is sufficient for
maintenance purposes.
HDm and HDc are measured during a predefined number of revolutions and automatically displayed.
Life time
HDm
HDc
HDm
HDc
HDm
HDc
To Next Page
Loading...
