Twa Alarm; Stel Alarm - Honeywell GasAlert Max XT II User Manual

GasAlertMaxXT II
User Manual

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 Resetting Gas Alarm Setpoints
setpoints.
2. Enter the TWA alarm setpoint for the H
sensor in the TWA Alarm (ppm) field. TWA is not appli-
cable to O and LEL.
2
3. Enter a value (4-16 hours) in the TWA Period (hours)
field to define the duration of the moving average. For
more information, refer to
30
for factory alarm
S and the CO
2
TWA Period (hours).

STEL Alarm

The short term exposure limit (STEL) is the maximum permissible gas
concentration a worker can be safely exposed to for short periods of time
(5-15 minutes maximum).
Standard factory alarm setpoints vary by region. Refer to
Resetting Gas Alarm Setpoints
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. Refer to
Note
for OSHA factory settings.
STEL Interval.