US
DESCRIPTION MSA
18
ALTAIR 5 - Operating Manual
2.4.3 Short Term Exposure Limits (STEL page)
WARNING
If the STEL alarm activates, leave the contaminated area immediately;
the ambient gas concentration has reached the preset STEL alarm level.
Failure to follow this warning will cause over-exposure to toxic gases and
persons relying on this product for their safety could sustain serious
personal injury or death.
Monochrome display
Color display
STEL
This page shows the average exposure over a 15-minute period.
When the amount of gas detected by instrument is greater than the
STEL limit:
•
Alarm sounds, alarm lights flash.
•
Alarm LEDs flash
•
“
STEL ALARM
” message flashes.
To reset the STEL:
(1) Access the STEL page.
(2) Press
the
button.
The STEL alarm is calculated over a 15-minute exposure.
STEL calculation examples:
Assume the instrument has been running for at least 15 minutes:
15-minute exposure of 35 ppm:
(15 minutes x 35 ppm)
15 minutes
= 35 ppm
10-minute exposure of 35 ppm and 5 minutes exposure of 15 ppm:
(10 minutes x 35 ppm) + (5 minutes x 5 ppm)
15 minutes
= 25 ppm