Warning; Time Weighted Average (Twa) (Figure 3-13) - MSA Orion Manual De Operaciones

Operating Manual
• 10-minute exposure of 35 PPM
5-minute exposure of 5 PPM:
(10 minutes x 35 PPM ) +
15 minutes
Assume the Orion Multigas Detector was turned on five minutes ago.
• 5-minute exposure of 15 PPM:
(5 minutes x 15 PPM ) + (10 minutes
15 minutes
If the STEL alarm condition is reached while using the
instrument as a personal or area monitor, 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, which can result in serious personal injury or
death.

Time Weighted Average (TWA) (FIGURE 3-13)

• The TWA flag will
appear in the upper
portion of the display
to show the average
exposure since the
TWA reading was
reset.
• When the amount of
gas detected by the
Orion Multigas
Detector is greater
than the eight-hour
TWA limit:
• Alarm Sounds
• Alarm Lights
Flash
• The TWA
flag flashes.
Chapter 3, Using the Orion Multigas Detector
(5
5 PPM )
x
minutes
0 PPM )
x

" WARNING

Figure 3-13. Exposure Page with TWA
Alarm
= 25 PPM
= 5 PPM
3-15