Svantek SVAN 979, Руководство пользователя

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47
SVAN 979 User Manual
Gradient trigger
The Grad + trigger starts the 1-second measurement/integration on condition:
value of the measured result ( Source ) averaged by 0.5 ms is greater than the
threshold value ( Level ) and the gradient of this Source is greater than the
gradient threshold value ( Gradient ). In other cases, the instrument continues
checking the trigger condition every 0.5 ms.
This trigger has the same logic as the Level + trigger, but the trigger condition requires also the gradient
threshold level to be exceeded.
External trigger
When External is selected, the measurement is triggering by the external signal
on the I/O socket. In this case, it is necessary to set up the I/O Mode parameter
as Digital In ( path: < Menu> / Instrument / Multifunction I/O ).
After the measurement/integration start from the external trigger, the
measurement/integration will continue for the
Integration Period .
Note: When a measurement is waiting for the gradient or external
trigger the “trigger” icon appears alternatively with the „measurement”
icon.
Source result
Only one measured result ( Source ) can be used for checking trigger condition in the Level Meter mode, namely
the instantaneous RMS from the first profile (with appropriate filter and detector), which is denoted here as
Leq(1) in the sound mode and RMS(1) in the vibration mode. This position cannot be changed.
Threshold level
The threshold level for the measurement
trigger (
Level ) can be set with 1 dB step in
the range from 24 dB to 136 dB in sound
modes and from 64dB (1.585mm/s
2
) to
176dB (631 m/s 2 ) in vibration modes.
Rate of Source value changing
This position appears when the Grad+ trigger is chosen. The rate of the Source
value changing ( Gradient ) can be set in the range from 1 dB/ms to 100 dB/ms.
4.3 S
ETTING PARAMETERS FOR PROFILES
–
P
ROFILES
The Profiles list enables programming of
three virtual level meters (Profiles), which
measure the set of results with the same
weighting filter (
Filter ) and exponential
detector time constant ( Detector ) (see
Appendix D). Default values
– see
Chapter 2.7 .
<ENT>