To Reset The Twa; Warning - MSA Sirius Mode D'emploi

• When the amount of gas detected by the Sirius Multigas Detector
is greater than the eight-hour TWA limit:
• Alarm Sounds
• Alarm Lights Flash
• TWA flashes.

To Reset the TWA:

1. Access the TWA page.
2. Press the RESET/
The TWA alarm is calculated over an eight-hour exposure. Calculation
examples are as follows:
• 1-hour exposure of 50 PPM:
(1 hour x 50 PPM) + (7 hours x 0 PPM)
• 4-hour exposure of 50 PPM
4-hour exposure of 100 PPM:
(4 hours x 50 PPM) + (4 hours x100 PPM)
• 12-hour exposure of 100 PPM:
(12 hours x 100 PPM)
8 hours
NOTE: The accumulated reading is always divided by eight hours.
If the TWA alarm condition is reached while using the instru-
ment as a personal or area monitor, leave the contaminated
area immediately; the ambient gas concentration has
reached the preset TWA alarm level. Failure to follow this
warning will cause over-exposure to toxic gases, which can
result in serious personal injury or death.
3-20
button.
8 hours
8 hours
= 150 PPM

" WARNING

"
= 6.25 PPM
= 75 PPM