MSA altair 5 - Page 20

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DESCRIPTION MSA
20 ALTAIR 5 - Operating Manual
To reset the MIN readings:
(1) Access the MIN page.
(2) Press the
button.
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 Colour 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