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Function
Equation
Vibration
Dose Value
(VDV)
VDV
0
T
ta
( )
a
w
4
ta
( )
d
1
4
ms
1.75
T = total measured integration time (seconds)
a
w
(ta) = instantaneous acceleration value
(ta) = time (seconds)
VDV
shift
VDV
shift
VDV
Exp
t
0.25
ms
1.75
VDV = Vibration Dose Value
Exp = Exposure Time (Seconds)
t = Measurement Log Duration (Seconds)
Vector Sum
(HARM)
VSum
X
( )
2
Y
( )
2
Z
2
X = X Axis Aeq
Y = Y Axis Aeq
Z = Z Axis Aeq
Vector Sum
(WBV)
VSum
1.4X
(
)
2
1.4Y
(
)
2
Z
2
X = X Axis Aeq
Y = Y Axis Aeq
Z = Z Axis Aeq
Dominant
Axis
(HARM)
Largest Aeq value from the X, Y and Z axis readings
Dominant
Axis
(WBV)
Largest Aeq value from the X, Y and Z axis readings
Where the X and Y axis are subject to a multiplication
factor of 1.4
Partial Ai(8)
(Vector Sum)
Ai 8
( )
Vsum
Exp
28800
Vsum = Vector Sum (HARM or WBV)
Exp = Exposure Time (Seconds)
Partial Ai(8)
(Dominant
Axis)
Ai 8
( )
dom
Exp
28800
dom = Dominant Axis (HARM or WBV)
Exp = Exposure Time (Seconds)
Daily
Exposure
A 8
( )
Ai 8
( )
1
2
Ai 8
( )
2
2
Ai 8
( )
n
2
Ai(8) = Partial Exposures (Vector Sum or Dominant Axis)
