Spectrum Analyzer

An instrument that displays the frequency spectrum of an input signal.

Spectrum

A display of discrete frequencies and their amplitudes.

Signal Analysis

Process of extracting information about a signal’s behavior in the time domain and/or frequency domain. Describes the entire process of filtering, sampling, digitizing, computation, and display of results in a meaningful format.

Sensitivity

The ratio of magnitude of an output to the magnitude of a quantity measured. Also the smallest input signal to which an instrument can respond.

SEE Technology (Spectral Emitted Energy)

The analysis process where the high frequency acoustic signals generated when the rolling element in a bearing passes over a flaw in the bearing surface. The signals are emitted by the microscopic movement of the metal crystals as they rub against each other. These signals are then enveloped and presented in the low frequency spectrum. The display signal will be at the characteristic bearing frequencies, BPFO, BPFI, etc.

Spline bore

A bore that has a series of parallel slots formed internal to the bore and mating with corresponding grooves cut in a shaft. The most common spline Bores conform to standards published by other organizations such as SAE, ISO, DIN, and ANSI and are in the form of involutes or have straight parallel sides.

Straight (Finished) bore

A concentric axial cylindrical hole finished to tolerances appropriate for mounting.

Swing diameter

The maximum diameter of the circular path described by rotating a universal joint.

Solo plate coupling

An auxiliary device required to rigidly hold in alignment the floating sleeve at the drive end of a flex hub coupling to allow solo operation of the driver without the need to dismount the coupling hub. Also known as an adapter plate.

Spacer gap length

The flange-to-flange dimension between coupling hubs or sleeves in which the coupling spacer is installed. Spacer gap length is not necessarily equal to the distance between the shaft ends.