9 Appendix
│
99
STEL: Main alarm (Short Time Exposure Limit)
Adjustable:
Yes
Latching:
Yes
Trigger:
The sum of the concentrations of a gas is greater than
the product of the Occupational Exposure Limit and
the excess factor over the averaging time
Indicator:
– audible signal
– visual signal
–
STEL
symbol
Acknowledge-
ment:
Not possible
Reset:
– by changing the application
–
by switching off the device
LTEL: Main alarm (Long Time Exposure Limit)
Adjustable:
Yes
Latching:
Yes
Trigger:
The sum of the concentrations of a gas is greater than
the Occupational Exposure Limit over the averaging
time
Indicator:
– audible signal
– visual signal
–
LTEL
symbol
Acknowledge-
ment:
Not possible
Reset:
– by changing the application
–
by switching off the device
9.4.2
Setting ranges
Note:
Alarms and LEL can only be changed using the
GasCom
soft-
ware.
●
In the
GasCom
software, the values are set in % LEL and
displayed in % vol.
●
In principle:
AL1
<
AL2
<
AL3
● For flammable gases,
AL2
must be at least 3 % LEL greater
than
AL1
.