Instruction manual

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WARNING
If the STEL alarm condition is reached while using the
instrument as a personal or area monitor, leave 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.
The STEL alarm is calculated over a 15-minute exposure.
Calculation examples are as follows.
Assume the FiveStar Alarm 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
5-minute exposure of 5 PPM:
(10 minutes x 35 PPM ) +
(5 minutes x 5 PPM )
15 minutes
= 25 PPM
Assume the FiveStar Alarm was turned on five minutes ago.
• 5-minute exposure of 15 PPM:
(5 minutes x 15 PPM ) + (10 minutes
x 0 PPM )
15 minutes
= 5 PPM
Press the PAGE button to move to:
Time Weighted Average (TWA)
TWA is the average exposure since the TWA reading was reset.
The TWA reading may be reset using the following procedure:
• Turn the FiveStar Alarm OFF for eight or
more hours or
• Press the PAGE button until the TWA
screen appears
• Press the RESET button; the
"Reset TWA" message appears
on the display.
• Press the RESET (YES) button.
Figure 2-34.
Reset TWA Page
Chapter 2, Using the FiveStar Alarm Instruction Manual
2-18 FiveStar Alarm