About the unit of measurement

The Anderon unit was established in the Unites States in the 1940s. The term was coined from an English word referring to the angle differential of a radial displacement. This unit of measurement is used to express the amount of vibration. The Anderon unit expresses the value calculated by dividing the effective value [µinch/rad], obtained by passing the radial vibration displacement [µinch] of the outer race of a bearing resulting from the rotation of its inner race through a band-pass filter with a displacement density [µinch/rad] differentiated by the angle of rotation [rad], by the square root of the passband octave. When 1,800 r/min, 50 to 10.8 kHz, is divided equally into L, M, and H, one Anderon equals 7,698 µm/s.

The Anderon meter calculates the displacement density [m/rad] from the vibration velocity [m/s] detected by the contact-type velocity sensor and the inner race rotation speed [rad/s], then displays the value obtained after normalizing the effective value based on bandwidth.

We can obtain Displacement [m] (1) by integrating the velocity [m/s] (2) over time.
We can obtain Acceleration [m/s^2] (3) differentiating the velocity [m/s] (2) with respect to time.
The effective value (4) is the average amplitude of oscillatory waveforms obtained using the root mean square.
Wave height value (5) is the maximum amplitude of the oscillatory waveform resulting from deviation from the standard.
Peak-to-rms ratio (6) is the ratio of wave height value (5) to effective value (4).

Waviness means undulation. Waviness of the circumferential surfaces of bearing parts such as inner race, outer race, and balls, as well as rollers causes Anderon vibration. When manufacturing bearing parts, we need to measure and manage the waviness of the circumferential surfaces of parts used around shaft. A wavimeter detects waviness and displays a value processed by a bandpass filter. The low pass region is for evaluating shape, while the high pass region is for evaluating surface roughness.