Honeywell BW MaxXT II - TWA Period Configuration; TWA Period Setting for Moving Average

1. Refer to the applicable regulatory requirements in your area for defining STEL alarm
setpoints.
2. Enter the setpoint in the STEL Alarm (ppm) field.
3. After entering the STEL setpoint, the STEL interval value (5-15 minutes) must be
entered.
TWA Alarm
The time-weighted average (TWA) is a safety measure used to determine accumulated
averages of gases. An average is determined using the Occupational Safety and Health
Administration (OSHA) method to ensure the worker leaves an area when the maximum
average is accumulated.
OSHA: The OSHA method is defined as a moving average that accumulates over an 8-hour
average. If the worker is in the field longer, the oldest accumulated values (first hour) are
replaced by the newest values (ninth hour). This continues for the duration of the work shift
until the detector is deactivated.
1. Refer to See "Resetting Gas Alarm Setpoints" on page62 for more information. for
factory alarm setpoints.
2. Enter the TWA alarm setpoint for the H
2
S and the CO sensor in the TWA Alarm (ppm)
field. TWA is not applicable to O
2
and LEL.
BW MaxXT II 44 User Manual