Larson Davis HVM100, Руководство пользователя

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B-4 HVM100 User Manual 4/11/03
Short Term
Maximum Peak
Peak = peak level of the instantaneous weighted acceleration,
a
w
(t); measured during one Averaging time period.
The peak measurement period is controlled by the Averaging time setting; a
new Peak value is calculated and displayed at the end of each Averaging
time period.
Long Term Crest
Factor
The CFmp measurement period is from Run to Reset; the display is updated
once per second.
Short Term
Crest Factor
The CF measurement period is controlled by the Averaging time setting; a
new CF value is calculated and displayed at the end of each Averaging time
period. CF is not calculated if the Averaging time setting is SLOW.
Summed
Instantaneous
Acceleration
a
w
∑
(t) = instantaneous, summed acceleration
a
wx
(t), a
wy
(t), a
wz
(t) = X, Y, and Z axis instantaneous acceleration
K
x,
K
y,
K
z
= X, Y, and Z axis Sum Factors
The HVM100 uses the formula above to calculate the instantaneous,
summed acceleration, a
w
∑
(t). This value is then used to calculate a sum
quantity for the A
rms
, A
eq
, Peak, VDV, and other metrics.
Description Equation
CFmp
Amp
Aeq
-----------
=
CF
Peak
Arms
-------------
=
K
x
a
wx
t
) ] ( [
2
K
y
a
wy
t
) ] ( [
2
+ K
z
a
wz
t
) ] ( [
2
+