Svantek SVAN 979 - Vibration Level Meter; Basic Terms and Definitions (VLM Mode); D.2.2 Definitions and Formulas of the VLM Result

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SVAN 979 User Manual - Appendixes
D.2. VIBRATION LEVEL METER
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).
( )
ta
W
instantaneous frequency-weighted signal with the weighting filter W.
( )
ta
W
instantaneous frequency and time-weighted
signal with the weighting filter W and time
constant

calculated from the equation:
( ) ( )
( )

−
=
−−


t
/t
dea
1
ta
2
WW
,
where:

– variable of integration.
( )
tv
instantaneous vibration signal depends on the
<RMS Integration> parameter:
( )
( )
( )



=
=

=
Exp nIntegratioRMS
Lin nIntegratioRMS
ta
ta
tv
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 = …