8
2.
Operation
To maintain proper operation of the transmitter it is neccesery to respect the fact, that the presence of certain concentrations
of gases or vapors, other than those for which the sensor is set, can cause an alarm, even if the concentration of the gas does
not exceed the set level. Given the range of disturbing gases or vapors (diluents, exhaust gases, vapors of organic substances,
disinfectants, etc.) a generally allowable concentration of interfering gases can not be determined. Data on cross-sensitivity to
certail gases are included at the apporpriate sensors. Therefore before processing project documentation we recommend to
have the air in the deployment area of the detection system analyzed.
3.
Operation/Maintenance
In case of contamination the surface can be cleaned with a slightly moistened cloth.
The seonsors have a different lifetime depending on the sensing technology used, and environmental conditions.
Characteristics of the sensors vary over time. Therefore it is required to perform regular checks and calibrations, which can be
done in two ways:
a)
1x every six months
carry out a „
calibration“ and functional control
-
adjust the sesitivity of the sensor using calibration
gas and check the functionality of the system. The exact interval depends on the purity of the environment, required
accuracy and the occurrance of disturbing gases in the atmoshpere.
b)
1x every twelve months
carry out a „
calibration“
-
adjust the sesitivity of the sensor using calibration gas and check the
functionality of the system. The exact interval depends on the purity of the environment, required accuracy and the
occurrance of disturbing gases in the atmoshpere. Also carry out a
„functional
control" 1 x every three months -
checking the function of the entire detection system using a test gas, which does not exceed the range of the sensor.
We recommend using gas intended for laboratory use.
For the „functional control“ do not use means
for testing fire alarm detectors!
Perform calibration only at certified service centers with a valid certificate of competence or the manufacturer.
For the Czech Republic only DEGA CZ s.r.o.
Accessories
1.
Additional bushing DEGA BUSHING for NBxIII
PG9
Basic types of transmitters
1.
Transmitters with a catalytic sensor NBx-CL III
Transmitter type
Detected gas
Measurement
range
Measurment of
current loop
(4-20mA)
Standard alarm setting
Resolution
Calibration gas
DEGA NBM-CL III
Methane (CH
4
)
Natural gas
CNG
0
–
100% LEL
0-20% LEL
1. st. 5% LEL, 2. st.10% LEL
3. st. 15% LEL, 4. st. 20% LEL
0,1% LEL
Methane 0,88 %
DEGA NBP-CL III
Butane (C
4
H
10
)
Propan-Butane
LPG
0
–
100% LEL
0-20% LEL
1. st. 5% LEL, 2. st.10% LEL
3. st. 15% LEL, 4. st. 20% LEL
0,1% LEL
Butane 0,32 %
DEGA NBH-CL III
Hydrogen (H
2
)
0
–
100% LEL
0-20% LEL
1. st. 5% LEL, 2. st.10% LEL
3. st. 15% LEL, 4. st. 20% LEL
0,1% LEL
Hydrogen 0,8 %
DEGA NBB-CL III
Gasoline vapors
0
–
100% LEL
0-20% LEL
1. st. 5% LEL, 2. st.10% LEL
3. st. 15% LEL, 4. st. 20% LEL
0,1% LEL
Hexane 0,18 %
DEGA NBA-CL III
Ammonia
0
–
100% LEL
0-20% LEL
1. st. 5% LEL, 2. st.10% LEL
3. st. 15% LEL, 4. st. 20% LEL
0,1% LEL
Methane 0,88 %
DEGA NBHFO-CL III
HFO Refrigerants
0
–
100% LEL
0-20% LEL
1. st. 5% LEL, 2. st.10% LEL
3. st. 15% LEL, 4. st. 20% LEL
0,1% LEL
Methane 0,88 %
DEGA NBL-CL III
Other flammable
and combustible
gases and vapors
0
–
100% LEL
0-20% LEL
1. st. 5% LEL, 2. st.10% LEL
3. st. 15% LEL, 4. st. 20% LEL
0,1% LEL
According to the
selectivity of the
sensor
