Conference_programme: 23: Structural acoustics and vibration
Lecture: Measurements and limits of vibration affecting the sensitive equipment s of some Metrological laboratories
Author(s): M.El-Basheer Tarek, A.Shawky Hany
Summary:
Precision equipment that can be affected by vibration is utilized in industry like calibration, fabrication of precise equipment, research involving laser beams for the measurement. The precision that is required is in the order of magnitude of 10-6 m to 10-12 m. The tenuous vibration or movement can cause the equipment to go out of tolerance. Establishment of appropriate vibration criteria is essential at the metrology institutes and is not easy. Vibration can damage the metrological equipment while a high level of vibration may lead to unsatisfactory of the measurement results. Some of NIS researchers at the length metrology division have complaints arising from vibrations which cause the measurements failure. The Length precision metrology building is highly isolated from both vibration and noise but opening the door of the laboratory and also foot walking inside might be the reason for the vibration. A new reason for vibration discovered from the base which is the raised floor that present at about 0.5m above the basic concrete. Steel base was mounted on the concrete and under the optical table to prevent the vibration. Vibration analysis carried out on 1/3 octave band frequency by means of accelerometer, the velocity was measured before and after mounting the steel base. The results showed that velocity minimized to be 6.2 µm/s( 2.5-25Hz)& 3.3µm/s(31.5-100Hz) after mounting the steel base. This paper aims at studying the sources of vibration at some laboratories in NIS length precision metrology division. Also, performing the 1/3 octave band frequency analyses to identify the frequencies of interest and its amplitude, then comparing with the criteria of vibration for the sensitive equipment’s at the metrology institutes. To find simple and budget friendly method to control vibration at the laboratories. Also, finding the limits of vibration for metrological/research institutes like NIS.
Corresponding author
Name: Dr Tarek M.El-Basheer
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Country: Egypt
