Warning - MSA Orion Operation Manual

Chapter 3, Using the Orion Multigas Detector
To Reset the TWA:
1. Access the TWA page.
2. Press and hold the CHANGE/RESET button until the TWA
flag flashes.
3. Push the ON-OFF/PAGE button to reset the TWA.
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 )
8 hours
• 4-hour exposure of 50 PPM
4-hour exposure of 100 PPM:
(4 hours x 50 PPM) + (4 hours x 100 PPM )
8 hours
• 12-hour exposure of 100 PPM:
(12 hours x 100 PPM)
8
hours
NOT E : The accumulated reading is always divided by
eight hours.
If the TWA 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 TWA alarm level.
Failure to follow this warning will cause over-exposure to
toxic gases, which can result in serious personal injury or
death.
3-16
= 6.25 PPM
= 75 PPM
= 150 PPM

WARNING

Operating Manual