The ability to take accurate measurements of vibration emissions and immissions is the basis of a vibration-avoidance program in accordance with legal regulations. DIN 4150 (German Institute of Norming) provides guidelines for evaluating vibrations in a frequency range of between 1 and 80 Hz in buildings in which people are present. The guidelines described in this norm can be used to judge periodic and non-periodic vibrations. The purpose of the norm is to provide for vibration protection within the framework of immission protection. Requirements and reference values are named that, when adhered to, will prevent people from being disturbed in their apartments and similarly-used interior spaces.
Vibration analysis with geophone
Very precise vibration analysis in the lower frequency range can be conducted with a highly-sensitive geophone. Vibration speeds of under 0.01µm/s in the range of 0.2 to 30Hz can be recorded with a geophone. Especially in the semiconductor, nanotechnology, and ultra-precise 3D measurement industries it is necessary to conduct very precise vibration measurements in order to guarantee an optimal and client-specific configuration.
The first step is to determine the maximum measured vibrations for each of the three vectors x, y and z. The largest of the three values is to be compared to the reference values Au and Ao from Table 1:
- If KB F max is equal to or lower than the (lower) reference value Au, then the norm’s requirements are met.
- If KB F max is larger than the (upper) reference value Ao, then the norm’s requirements are not met.
- In the case of rarely-occurring vibration or impulses, the norm’s requirements are considered met if KB F is lower than Ao.
Another current example for the necessity of vibration analysis is mounting ultra-accurate 3D measurement machines as well as other testing, measurement, or grinding machines.
On location measurement of vibration
It is typically necessary to conduct measurements at the location of the future installation of such machines in order to guarantee that existing floor vibrations do not exceed the maximum allowed values. Vibrational accelerations are measured within a defined frequency range, (1-100 Hz) as a simple sum value measurement cannot provide a sufficient amount of information about the exact conditions. Evaluation of the force-distance signal is conducted with a Fast Fourier Analyzer that displays a measured value for each frequency of the spectrum. (vibration acceleration in g)
In case the disturbances (vibration immissions) exceed the permissible range, our PC calculation software can help to ascertain the suitable isolation.