83
7 Appendix
7.5.2.3 Hydrogen sulphide H
2
S
Type:
Electrochemical sensor
Measuring range:
– Lower limit
0 – 100 ppm
1 ppm
Resolution:
1 ppm
Measuring error:
±3 % / ±3 ppm (±3 digits)
±2 ppm (long-term stability) as per
Zero point deviation:
1 ppm
Response time:
t
90
< 30 s
Decay time:
t
10
< 27 s
Drift:
< 10 % within 6 months
Temperature range:
-20 ºC – +40 ºC
Alarm thresholds
(factory settings):
AL1: 10 ppm
AL2: 20 ppm
AL3: 100 ppm
Interference at 20 ºC.
– 100 ppm CO
– 1 % vol. H
2
– 100 ppm NO
2
Approx. 1 ppm H
2
S
Approx. 10 ppm H
2
S
Approx. 3 ppm H
2
S
Lifetime:
– Warranted
– Expected
2 years
> 3 years
Test gases:
– Zero point
– Sensitivity
Fresh air
40 ppm H
2
S
7.5.3
Gas-sensitive semiconductor
Methane CH
4
, propane C
3
H
8
Type:
Gas-sensitive semiconductor
Measuring range:
0 – 1 % vol.
Resolution:
1 ppm / 2 ppm / 20 ppm / 200 ppm
Measuring error:
±30%
Alarm thresholds
(factory settings):
3 ppm
Interference at 20 ºC.
All hydrocarbons C
x
H
y
Lifetime:
– Warranted
– Expected
1 year
5 years
Test gases:
– Zero point
– Sensitivity
Fresh air
10 ppm / 100 ppm / 1000 ppm / 1.0 % vol
