LR/HR Measurements
The transducer type and measuring procedure are the same as for the dBm/dBc method. Shock pulses from the bearing are propagated through the material and picked up by the transducer. The transducer converts the shocks to electric signals, which are processed to provide a carpet value and a peak value.
The shock pulse meter counts the rate of occurrence (incoming shock pulses per second) and varies the measuring threshold until two amplitude levels are determined:
- HR - high rate of occurrence, quantifying the shock carpet (approx. 1000 incoming shocks per second)
- LR - low rate of occurrence, quantifying the strong shock pulses (approx. 40 incoming shocks per second)
*The LR/HR method requires more precise data on the bearing. The bearing geometry, as well as size and speed, affect the shock carpet and thus the analysis of oil film condition in healthy bearings. The rpm is needed, as well as a definition of the bearing type and size, ideally input by stating the ISO bearing number, which links to the bearing catalog in the Condmaster software.
The shock carpet and peak values, along with the bearing geometry, size, and speed provide an evaluation of the bearing lubrication and potential damage. After the measurement, the following information is provided:
- General description of bearing condition (CODE)
- Value for oil film condition (LUB)
- Value for surface damage (COND)