Vibration measurements for the evaluation of the detachment of plaster

The evaluation of the phenomenon of detachment of the plaster inside and outside of buildings is a problem that can not be overlooked, since it is often a prelude to the sudden fall of pieces of plaster or ceiling that may be dangerous to people.

A non-invasive approach that can be useful to the objective assessment and reliable of the detachment of the plaster is the acousto-optic technology: an acoustic wave, with variable frequency from several tens to several hundreds of Hertz, is directed to the area of investigation and at the same time, a laser sensor with high sensitivity measures the vibrations induced locally on the structure.

Julight Laser Vibrometers represent a smart, clean, fast and accurate solution to evaluate the detachment of the plaster or ceiling.

Pictures show the measurement set-up, together with vibration spectra measured on a “good” and “poor” portion of the plaster. The graphs clearly show the different frequency response of the “good” and “poor” plaster.

JVSM400_intonaci_SWEEP Slow_Rotel4e0_DISTACCO_TRAVETTO_001_FFT_risposta_in_frequenza_all

 

Comparison of the frequency response of “good” and “poor” plaster.