Binder CB 170, Operating Manual

Page: 18 / 175

CB (E7) 06/2018 Page 18/174
1.10 Resistance of the humidity sensor against harmful substances
The following list of harmful substances refers only to the humidity sensor and does not include any other
materials incorporated in the chamber or prohibited substances in relation to explosion protection.
Some gases - especially clean gases - do not have any influence on the humidity sensor. Others do have
a very small influence, whereas others may influence the sensor to a larger extent.
•
The following gases do not influence the sensor and the humidity measurement: Argon (Ar), carbon
dioxide (CO
2
),helium (He), hydrogen (H
2
), neon (Ne), nitrogen (N
2
), nitrous oxide (N
2
O), oxygen (O
2
)
•
The following gases do not or to a minor extent influence the sensor and the humidity measurement:
Butane (C
4
H
10
), ethane (C
2
H
6
), methane (CH
4
), natural gas propane (C
3
H
8
)
•
The following gases do not, or to a minor extent influence the sensor and the humidity measurement,
provided that the indicated loads are not exceeded:
Maximum work place
threshold limit value Tolerated concentration
with permanent load
Substance Formula ppm mg/m
3
ppm mg/m
3
Ammonia NH
3
20 14 5500 4000
Acetone CH
3
COCH
3
500 1200 3300 8000
Benzene 300 1200 150000
Chlorine Cl
2
0.5 1.5 0.7 2
Acetic acid CH
3
COOH 10 25 800 2000
Ethyl acetate CH
3
COOC
2
H
5
400 1400 4000 15000
Ethanol C
2
H
5
OH 500 960 3500 6000
Ethylene glycol HOCH
2
CH
2
OH 10 26 1200 3000
Formaldehyde HCHO 0.3 0.37 2400 3000
Isopropanol (CH
3
)
2
CHOH 200 500 4800 12000
Methanol CH
3
OH 200 260 3500 6000
Methyl ethyl ketone C
2
H
5
COCH
3
200 590 3300 8000
Ozone O
3
0.1 0.2 0.5 1
Hydrochloric acid HCl 2 3 300 500
Hydrogen sulphide H
2
S 10 15 350 500
Nitrogen oxides NOx 5 9 5 9
Sulphur dioxide SO
2
5 13 5 13
Toluol C
6
H
5
CH
3
100 380 1300 5000
Xylene C
6
H
4
(CH
3
)
2
100 440 1300 5000
These values are to be considered as approximate values. The sensor resistance largely depends on
the temperature and humidity conditions during the time of exposure to harmful substances. Avoid
simultaneous condensation. Tolerated error of measurement: ± 2 %r.H. The maximum work place
threshold limit value is one that can be regarded as harmless for humans.
•
Vapors of oil and fat are dangerous for the sensor because they may condensate at the sensor and
thus prevent its function (insulating layer). For similar reasons it is not possible to measure smoke
gases.