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Difference between revisions of "Human Vibration"
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======Aw====== | ======Aw====== | ||
The <math>A_w</math> is the RMS of the weighted acceleration signal. The weighting is applied in accordance with the direction set for each channel and the weighting filter defined for the direction. | The <math>A_w</math> is the RMS of the weighted acceleration signal. The weighting is applied in accordance with the direction set for each channel and the weighting filter defined for the direction.<br> | ||
For each channel, the <math>A_w</math> and <math>A_w(T)</math> will be calculated. The <math>A_w(T)</math> is the Daily exposure value, defined as : <br><br> | For each channel, the <math>A_w</math> and <math>A_w(T)</math> will be calculated. The <math>A_w(T)</math> is the Daily exposure value, defined as : <br><br> | ||
<math display="block" forcemathmode="5">A_w(T) = A_w*k_{i}*\sqrt{\frac{T_m}{T}}</math> <br> | <math display="block" forcemathmode="5">A_w(T) = A_w*k_{i}*\sqrt{\frac{T_m}{T}}</math> | ||
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With <math>T_m</math> the duration of the measurement and <math>T</math> the total exposure duration represented by the "Reference time" parameter. the <math>k_i</math> factor is defined in the ISO 2631 as <math>k_X = k_Y = 1.4</math> and <math>k_Z = 1</math>. | With <math>T_m</math> the duration of the measurement and <math>T</math> the total exposure duration represented by the "Reference time" parameter. the <math>k_i</math> factor is defined in the ISO 2631 as <math>k_X = k_Y = 1.4</math> and <math>k_Z = 1</math>. | ||
When comparing result from one measurement point in the three direction, the maximum of the Daily exposure value must be used as the total daily exposure value at that point :<br><br> | When comparing result from one measurement point in the three direction, the maximum of the Daily exposure value must be used as the total daily exposure value at that point :<br><br> | ||
<math display="block" forcemathmode="5">A_w(T) = max(A_{wX}(T), A_{wY}(T), A_{wZ}(T)) </math><br> | <math display="block" forcemathmode="5">A_w(T) = max(A_{wX}(T), A_{wY}(T), A_{wZ}(T)) </math> | ||
<br> | |||
======av====== | ======av====== | ||
The <math>a_v</math> is the total RMS vibration value of the weighted acceleration signal. This value will only be calculated if a sensor have been defined in the definition of direction window. | The <math>a_v</math> is the total RMS vibration value of the weighted acceleration signal. This value will only be calculated if a sensor have been defined in the definition of direction window. | ||
For each tri-axial sensor, the <math>a_v</math> will be calculated as a quadratic average of the weighted RMS value in the three directions :<br> | For each tri-axial sensor, the <math>a_v</math> will be calculated as a quadratic average of the weighted RMS value in the three directions :<br><br> | ||
<math display="block" forcemathmode="5">a_v = \sqrt{{a_{vX}}^{2}*{k_{X}}^{2} + {a_{vY}}^{2}*{k_{Y}}^{2} + {a_{vZ}}^{2}*{k_{Z}}^{2}}</math> | |||
<math display="block" forcemathmode="5">a_v = \sqrt{{a_{vX}}^{2}*{k_{X}}^{2} + {a_{vY}}^{2}*{k_{Y}}^{2} + {a_{vZ}}^{2}*{k_{Z}}^{2}}</math><br> | |||
With <math>k_{X,Y,Z}</math> a factor defined in the ISO 2631 as <math>k_{X}=k_{Y}=1.4</math> and <math>k_{Z}=1</math> | With <math>k_{X,Y,Z}</math> a factor defined in the ISO 2631 as <math>k_{X}=k_{Y}=1.4</math> and <math>k_{Z}=1</math> | ||
<br> | |||
======Ah====== | ======Ah====== | ||
The <math>A_h</math> is the RMS of the <math>W_h</math> weighted acceleration signal for hand-arms vibration measurement. <br> | The <math>A_h</math> is the RMS of the <math>W_h</math> weighted acceleration signal for hand-arms vibration measurement. <br> | ||
For each channel, the <math>A_h</math> and <math>A_h(T)</math> will be calculated. The <math>A_h(T)</math> is the Daily exposure value, defined as : <br> | For each channel, the <math>A_h</math> and <math>A_h(T)</math> will be calculated. The <math>A_h(T)</math> is the Daily exposure value, defined as : <br><br> | ||
<math display="block" forcemathmode="5">A_h(T) = A_h*\sqrt{\frac{T_m}{T}}</math> | |||
<math display="block" forcemathmode="5">A_h(T) = A_h*\sqrt{\frac{T_m}{T}}</math> <br> | |||
With <math>T_m</math> the duration of the measurement and <math>T</math> the total exposure duration represented by the "Reference time" parameter. | With <math>T_m</math> the duration of the measurement and <math>T</math> the total exposure duration represented by the "Reference time" parameter. | ||
If any sensor is defined, the total <math>A_h</math> and <math>A_h(T)</math> will be calculated for each sensor as a quadratic average of the three direction of the sensor : <br> | If any sensor is defined, the total <math>A_h</math> and <math>A_h(T)</math> will be calculated for each sensor as a quadratic average of the three direction of the sensor : <br><br> | ||
<math display="block" forcemathmode="5">A_{h Total} = \sqrt{{a_{hX}}^{2}*{k_{X}}^{2} + {a_{hY}}^{2}*{k_{Y}}^{2} + {a_{hZ}}^{2}*{k_{Z}}^{2}}</math> | <math display="block" forcemathmode="5">A_{h Total} = \sqrt{{a_{hX}}^{2}*{k_{X}}^{2} + {a_{hY}}^{2}*{k_{Y}}^{2} + {a_{hZ}}^{2}*{k_{Z}}^{2}}</math> | ||
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and : <br> | and : <br> | ||
<br> | |||
<math display="block" forcemathmode="5">A_{h Total}(T) = \sqrt{{a_{hX}}^{2}*{k_{X}}^{2} + {a_{hY}}^{2}*{k_{Y}}^{2} + {a_{hZ}}^{2}*{k_{Z}}^{2}}*\sqrt{\frac{T_m}{T}}</math> | <math display="block" forcemathmode="5">A_{h Total}(T) = \sqrt{{a_{hX}}^{2}*{k_{X}}^{2} + {a_{hY}}^{2}*{k_{Y}}^{2} + {a_{hZ}}^{2}*{k_{Z}}^{2}}*\sqrt{\frac{T_m}{T}}</math> | ||
<br> | |||
With <math>T_m</math> the duration of the measurement and <math>T</math> the total exposure duration represented by the "Reference time" parameter, and <math>k_{X}=k_{Y}=k_{Z}=1</math> | With <math>T_m</math> the duration of the measurement and <math>T</math> the total exposure duration represented by the "Reference time" parameter, and <math>k_{X}=k_{Y}=k_{Z}=1</math> | ||
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======Peak====== | ======Peak====== | ||