Siemens Water Technologies Series Manual page 9

1.2 Interferences
WT.050.130.000.UA.IM.1108
ACUTEC™ 35 SYSTEM
Electrochemical sensors are, by nature, not 100% selective; therefore,
they can exhibit response to other gases present in ambient air.
The following tables list the possible interferences that may occur when
using the different gas sensors. The tables indicate the relative response
of the sensor to 1 ppm of the listed gas, expressed in terms of relative
ppm signal. For example: exposure of a chlorine sensor to a gas sample
containing 1 ppm of nitrogen dioxide (NO
to 0.4 ppm of chlorine. A negative sign (-) indicates an interference that
can cause low gas measurements if there is a mixture of the measured
gas and another gas.
Interference Gas
Bromine
Fluorine
Chlorine Dioxide
Ozone
Nitrogen Dioxide
Hydrogen Sulfide
Hydrogen Cyanide
Methyl Mercaptan
Sulfur Dioxide
Interference Gas
Nitrogen Dioxide
Hydrogen Cyanide
Nitric Oxide
Acetylene
Ethanol
Hydrogen
Bromine
Fluorine
Chlorine Dioxide
Ozone
3
) would produce a signal equal
2
CHLORINE
Response
1.0
1.0
1.0
1.0
0.4
-0.1
-0.05
-0.04
-0.01
SULFUR DIOXIDE
Response
0.8
0.15
0.04
0.02
0.05
0.005
-0.1
-0.1
-0.1
-0.1