Larson Davis HVM200, Manual

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HVM200 Reference Manual C-3
Running RMS
Acceleration
EXPONENTI
AL

Time constant of the measurement.
An averaging time of SLOW is equivalent to a time constant of
1 second.
Vibration Dose
Value
The
VDV
integration time is from Run to Reset; the display is
updated once per second. The
VDV
is not calculated for units of
dB org.
For whole body vibration mode:
VDV
sum
= max(VDV
x
+ VDV
y
+ VDV
z
)
Maximum
Transient
Vibration
Value
Amax = maximum reading of all Arms readings from Run to
Reset.
The display is updated at the end of each Averaging time
period.
Minimum
Transient
Vibration
Value
Amin = minimum reading of all Arms readings from Run to
Reset.
The display is updated at the end of each Averaging time
period.
Long Term
Maximum
Peak
Amp = peak level of the instantaneous weighted acceleration,
a
w
(t); measured over the entire measurement period, from Run
to Reset.
The displayed Amp value is updated once per second.
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.
Term Equation Description
Arms
1

---
a
w
2
t
 
t t
0

------
 
 
exp
t d

t
0

=
-
-
VDV a
w
4
t
 
t d
0
T

 
 
 
 
1
4
---
=