SV 977D User Manual - Appendixes
D.2. VIBRATION LEVEL METER
D.2.1 Basic terms and definitions (VLM mode)
current time period of the measurement in seconds.
exponential time constant in seconds for the given 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.
frequency-weighting filter (HP, HP1, HP3, HP10, Vel1, Vel3, Vel10, VelMF, Dil1, Dil3, Dil10,
or Wh).
instantaneous frequency-weighted signal with the weighting filter 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
– variable of integration.
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: