OPERATION OF AREARAE-Gamma
2-18
2.8 Alarm Limits & Calibration
AreaRAE-Gamma is factory calibrated with standard calibration
gas, and is programmed with default alarm limits as listed
below. (See Section 4.4 Calibration of AreaRAE-Gamma and
Section 4.5 Change Alarm Limits)
Table 2.3
Alarm Limits & Calibration
Gas ppm
Cal Gas/ Balance
Unit
TWA
STEL
Low
High
CO
50 / Air
ppm
35
100
35
200
H
2
S
10 / N
2
ppm 10 15 10 20
SO
2
5 / N
2
ppm 2 5 2 10
NO
25 / N
2
ppm 25 25 25 50
NO
2
5 / Air
ppm
1
1
1
10
Cl
2
10 / N
2
ppm
0.5
1
0.5
5
O
2
20.9 / N
2
% - -
19.5 23.5
CH
4
50 / Air
%LEL
-
-
10
20
HCN
10 / N
2
ppm 4.7* 4.7* 4.7* 50
NH
3
50 / N
2
ppm 25 35 25 50
PH
3
5 / N
2
ppm
0.3
1
1
2
VOC**
100 / Air
ppm
10.0
25.0 50.0
100
Gamma n/a µR/h
-
-
100
250
*The LCD display is truncated to show “5”.
**100 ppm isobutylene gas is used for VOC gas calibration.
