Svantek SVAN 979, User Manual

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SVAN 979 User Manual - Appendixes
D.2. V
IBRATION
L
EVEL
M
ETER
D.2.1 Basic terms and definitions (VLM mode)
T
current time period of the measurement in seconds.

exponential time constant in seconds for the giving time-weighting. The following time constants
are available:
100 ms , 125 ms , 200 ms , 500 ms , 1.0 s , 2.0 s , 5.0 s , 10.0 s.
W frequency-weighting filter ( HP , HP1 , HP3 , HP10 , Vel1 , Vel3 , Vel10 , VelMF , Dil1 , Dil3 , Dil10 ,
or Wh ).
( )
t a
W
instantaneous frequency-weighted signal with the weighting filter W .
( )
t a
W

instantaneous frequency and time-weighted
signal with the weighting filter
W and time
constant

calculated from the equation:
( ) ( )
( )

 −
  =

 − −


t
/ t
d e a
1
t a
2
W W
,
where:

– variable of integration.
( )
t v
instantaneous vibration signal depends on the
<
RMS Integration> parameter:
( )
( )
( )



=
=

=
Exp n Integratio RMS
Lin n Integratio RMS
t a
t a
t v
W
W
D.2.2 Definitions and formulas of the VLM result
The instrument calculates the vibration measurement results for three profiles. The calculation flow diagram for
one profile is presented below:
a
2
wτ
(t)
τ = 10s
τ = 100ms
a
w
(t)
a(t)
a
2
w
(t)
Peak, P-P
Max, MTVV
RMS
τ = …