A refrigerator oil composition contains base oil and polyalkylene glycol block copolymer. A plurality of intensity modulators receives each of the frequency components and passes each of the frequency components for a selective time period, and then extinguishes that frequency for the remainder of a chirp time, the plurality of intensity modulators producing a plurality of first output signals. The pitch bearing may also include an inner race defining a first inner raceway wall. The power board includes a power circuit board and an ACDC power module. The microprocessor samples and records the peak voltage and the microprocessor goes back to sleep. The mechanical energy provided in methods shown also can also be used with delicate surface features.