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Difference between revisions of "Human Vibration"
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→Whole-Body Measurement
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===Type of measurement=== | ===Type of measurement=== | ||
====Whole-Body Measurement==== | ====Whole-Body Measurement==== | ||
Measurement procedures for whole-body vibration evaluation are describe in the ISO2631. That type of vibration will mainly occur in transportations and in the workplace when working with big machinery. Therefore, the evaluation of the vibration will be carried on the part supporting the human body, like backside and feet for a seated person and feet for a standing person. Sensors must be placed to assess vibration to these specific points. Measurement must be carried on the complete system. Meaning the user must be present during the measurement and operate the machine/vehicle as usual. The following picture, | Measurement procedures for whole-body vibration evaluation are describe in the ISO2631. That type of vibration will mainly occur in transportations and in the workplace when working with big machinery. Therefore, the evaluation of the vibration will be carried on the part supporting the human body, like backside and feet for a seated person and feet for a standing person. Sensors must be placed to assess vibration to these specific points. Measurement must be carried on the complete system. Meaning the user must be present during the measurement and operate the machine/vehicle as usual. The following picture, extracted from the standard, give indication over the orientation of the sensors : <br> | ||
[[Image:Axis_WholeBody.png]]<br> | [[Image:Axis_WholeBody.png]]<br> | ||
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For each point, the vibration must be measured in the three direction X, Y and Z. AS different weighting will be used for each direction, it is really important that each sensors are oriented according to the same directions. The Z direction must always used in the direction of the human spine.<br> | For each point, the vibration must be measured in the three direction X, Y and Z. AS different weighting will be used for each direction, it is really important that each sensors are oriented according to the same directions. The Z direction must always used in the direction of the human spine.<br> | ||
Specific sensors must be used in order to detect vibration at the transmission point. For a seated person, [https://www.dytran.com/Model-5313A-Triaxial-Seat-Pad-Accelerometer-P2161/|Seat Pad accelerometer] allow to acquire vibrations at the | Specific sensors must be used in order to detect vibration at the transmission point. For a seated person, [https://www.dytran.com/Model-5313A-Triaxial-Seat-Pad-Accelerometer-P2161/|Seat Pad accelerometer] allow to acquire vibrations at the buttocks :<br> | ||
[[Image:DytranSeatPad.png]]<br> | [[Image:DytranSeatPad.png]]<br> | ||
If necessary, the same kind of sensors can by used under the feet of a standing person. These sensor must be fixed to hold in place when the subject move. For vibration transmitted to feet, standard accelerometers can also be placed on the floor.<br> | |||
[[Image:DytranSeatPad.png]]<br> | |||
The length of the measurement should be representative of the whole exposure duration during a day. However, as it is not always possible to acquire long signal, the ISO 2631 specify that measurement must be taken for at least 20 minutes, and 2h measurement are preferable. Using the OROS tool kit, long signals file can be take a lot of time to analyse. In order to analyse signal files longer than 30 minutes, we advise to : <br> | |||
* reduce the Sampling rate, as frequency bandwidth for Whole-body vibration will note exceed 1kHz. | |||
* Split each sensors over several files | |||
<br> | |||
Please contact OROS customer care team for advices. | |||
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====Hand-Arm Measurement==== | |||
Capteur avec adaptateurs hand arms | Capteur avec adaptateurs hand arms | ||