3M SP-DL-1, Руководство пользователя

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Speech Intelligibility
Selecting STI scale or CIS scale
Models SE and DL
STI scale
The scale identifies if the mass notification system is intelligible or unintelligible based
on a
STI scale
ranging from 0.0 to 1.0 where
0.5 to 1.0
is considered a passing
score, per NFPA 72 and IEC 60849.
Common Intelligibility Scale (CIS)
Similar to the STI scale, the CIS scale uses a range from 0.0 to 1.0 to determine if the
MNS is intelligible. However, with the
CIS scale
, a rating of
0.7 to 1.0
is an
“intelligible” score, per the IEC 608489 and NFPA 72.
When to take STI-PA readings?
Scenario one
You may be able to run the test signal through the PA system during normal
business hours. In this scenario, you would set the meter to STI-PA and select either
STI scale or CIS scale and run your study in the mapped “zone” areas.
Scenario two
In other situations, running a test tone through a PA system during business hours
could be distracting and not feasible for your environment. In this situation, it is
recommended to follow these procedures:
•
First,
take sample background noise measurements during business hours.
These are saved and stored on the Verifier as “Captured Curves”. The verifier
will save up to four “captured curves”
•
Second,
in the STI-PA options, select the appropriate captured curve.
•
Third
, run your measurements at the appropriate time of day (i.e., late
evening/early morning). (The applied captured curve will automatically factor
into your study.)
•
Fourth
, view your results on the display of the instrument (or in Excel by using
the File converter tool.)
STI
00 - 0.30 0.3 - 0.45 0.45 - 0.60 0.60 - 0.75 0.75 - 1.00
scale Unacceptable Poor Fair Good Excellent
CIS
00-0.48
0.48 - 0.65 0.65 - 0.78 0.78 - 0.88 0.88 - 1.0
scale Bad Poor Fair Good
Excellent