20
PRIVACY INDEX MEASUREMENTS
REQUIRED EQUIPMENT:
TALKBOX (requires 110vac or 8 AA Alkaline or Ni cad batteries)
DSP2BP (requires 110vac or 8 AA Alkaline or Ni cad batteries)
STI-PA CD test tones (included with DSP2BP & DSP30BP)
INSTRUCTIONS TO MEASURE PRIVACY (OPT PI)
PI measurements are made in occupied areas, typically with the sound masking system
turned on, and set to its normal levels.
1. Insert the STI-PA CD into the TalkBox and turn on.
2. Insert analyzer microphone into the Analyzer and turn on (will display dBA SPL)
3. Place the talk box loudspeaker in the general location where the person will be speaking
during normal use of the space and set the level on the TalkBox to 65dBA, as measured
with microphone approximately 1 meter (39”) from the TalkBox loudspeaker.
4. Place DSP2BP microphone in the area to be measured for privacy (adjoining cubicle,
adjoining room, etc).
5. To make a PI test, set the DSP2BP to the PI mode by pressing the (MODE SELECTOR)
on the bottom of the analyzer, until the PI LED is lit.
6. To start the test Press the
[TEST]
Button. Test results will display in 48 seconds.
7. If
“Err”
is displayed, press the
[dBA]
Button and repeat the test as reliable data could not
be collected. The PI Mode has an auto reject mode, if corrupted date is detected during
the test (slamming doors, other impulsive type noises). If this occurs, you will see the
numeric box stop its count down, and go back to the start of the sequence. If this auto-
detect/correct mode is successful, it will take slightly longer to test, but will display a
score. If too many errors are detected, it will instead display Err, and you need to re-run
the test. Remember that PI tests measure very low levels, so it is best to do this type of
work when it is relatively quiet in the room.
8. If the “BAT” symbol is shown, replace batteries.
Evaluating the results - PRIVACY
EXCELLENT
GOOD
FAIR
PI
1.00
.95
.94
.90
.89
.80
POOR
NO PRIVACY
PI
.79
.70
.69
0.00
