Accelerometer Frequently Asked Questions

A person's perception of vibration varies considerably depending on the frequency f of that vibration.

When 1 G (9.8 m/ ^s²) is represented by displacement X,

（mm）

The difference is significant: 0.025 mm at 100 Hz and 2.5 mm at 10 Hz.

A vibration level meter is a measuring instrument that expresses ground vibration and floor vibration as perceived by humans. It uses ^10⁻⁵ m/ ^s² as a baseline and expresses its magnification in dB (logarithmic scale).

 

1 G

It will be.

Furthermore, the vibrations that humans can perceive range from approximately 1 Hz to 100 Hz, and the way they are perceived (their intensity) changes depending on the frequency. This is called the vibration perception characteristic, and vibrations are most easily perceived between approximately 4 and 8 Hz, with the perception becoming less pronounced as the frequency deviates from this range. (Please refer to the VR-6100 catalog.)

Generally, the vibration level in dB is displayed as the vibration value obtained by correcting the above value using this vibration perception characteristic.

Furthermore, earthquakes have seismic intensity levels ranging from 0 to VII. (Although magnitude is now used instead.) The relationship between acceleration and seismic intensity is shown in the table below.

The relationship is 1G = 980 cm/ ^s² = 980 gal (1 gal = 1 cm/ ^s²).

 

Since the purpose is to analyze the effects of floor vibrations from installed machinery, frequency analysis is performed because, as mentioned above, frequency is a crucial factor in vibration.

As a unit of speed

1 kine = 1 cm/sec

There is.