MSA ALTAIR 4XR Operating Manual page 17

Time Weighted Average (TWA page)
WARNING!
If the TWA alarm activates, 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 and persons relying on this product for their safety could sustain serious personal injury or death.
The TWA icon ( chapter 2.3 "On-Screen Indicators") appears on the display to show the average
exposure since the device was turned on or since the TWA reading was reset. When the amount of
gas detected is greater than the eight-hour TWA limit:
• Alarm sounds
• Alarm LEDs flash
• TWA icon flashes.
To reset the TWA:
(1) Access the TWA page.
(2) Press the  button.
The TWA alarm is calculated over an eight-hour exposure.
TWA calculation examples:
1 hour exposure of 50 ppm:
(1 hour x 50 ppm) + (7 hours x 0 ppm)
4 hour exposure of 50 ppm and 4 hour exposure of 100 ppm:
(4 hours x 50 ppm) + (4 hours x 100 ppm)
12 hour exposure of 100 ppm:
(12 hours x 100 ppm)
This page can be deactivated through the MSA GALAXY GX2 Test Stand or MSA Link software.
Time Display
Current time appears on the display in a 12-hour format by default.
A 24-hour format can be selected using MSA GALAXY GX2 Test Stand or MSA Link.
Date Display
Current date appears on the display in the format: MMM-DD-YYYY.
Discoverable Mode page
Allows the user to put the device into Bluetooth discoverable mode in order to pair with another device.
This page can be deactivated through the BT SETUP page.
= 6.25 ppm
8 hours
= 75 ppm
8 hours
= 150 ppm
8 hours
®
ALTAIR 4XR
Description
US
17