IST-2237.EC01.01
Istruzione / User’s Manual / Manuel d’utilisation
Pag.8/20
TECNOCONTROL S.r.l. - Via Miglioli, 47 20090 SEGRATE (MI)
Tel. +39 02 26922890 - Fax +39 02 2133734
1-Modello
2-Gas da utilizzare
3-Flussomentro 4-TEST mA 5-Uscita in mA 6-Indicazione in ppm
SE237EA
100ppm Ammoniaca (NH
3
) in azoto
0,3 l/min
90÷96 mV
9,0÷9,6 mA
100 ppm
(±5)
SE237EA-H
1 l/min
SE237EC-S
300ppm Monossido di carbonio(CO) in azoto
0,3 l/min
190÷210 mV
19÷21 mA
300 ppm
(±20)
SE237EC-H
SE237ES
10ppm Biossido di zolfo (SO
2
)
in azoto
0,3 l/min
118÷122 mV 11,7÷12,3 mA
10.0 ppm (±0.5)
SE237EH
50ppm Idrogeno solforato (H
2
S) in azoto
0,3 l/min
117÷123 mV 11,7÷12,3 mA
50 ppm (±2)
SE237EHCN
10ppm Acido cianidrico (HCN) in azoto
0,3÷0,5 l/min
192÷208 mV 19,2÷20,8 mA
10.0 ppm (±1)
SE237EN
100ppm Ossido d’azoto (NO) in azoto
0,3 l/min
192÷208 mV 19,2÷20,8 mA
100 ppm (±5)
SE237EN2
30ppm Biossido d’azoto (NO
2
) in aria
1 l/min
190÷210 mV
19÷21 mA
30 ppm (±2)
SE237EHCL
10ppm Acido cloridrico (HCL) in azoto
0,3÷0,5 l/min
192÷208 mV 19,2÷20,8 mA
10 ppm (±1)
SE237ECL
10ppm Biossido d’azoto (NO
2
) in aria
1 l/min
192÷208 mV 19,2÷20,8 mA
10.0 ppm (±0,5)
EN
DESCRIPTION
The
SE237E
series are stand-alone gas detectors able to detect toxic gases by employing an electrochemical sen-
sor calibrated to different gases and find their best application in centralized alarm systems for parking, laborato-
ries, manufacturing industries and environments to be protected from possible leakage of gas.
The instruments comprise of a thermoplastic enclosure in which the electronic circuit and the terminals are mount-
ed and a downward facing cylindrical sensor housing with inside a
“Replaceable Cartridge Sensor
”.
The
SE237E
series have three alarm levels, with different set-up, depending on the models, as listed in
Tables 5÷11.
The outputs are relays with tension free single pole contacts
(SPST)
. The instrument has also a 4÷20mA linear output
(
S
) with F.S. of the detected gas, expressed in ppm
(part per million
). This output can be used to connect a remote
central unit and / or for Test and Calibration routine, code protected, by using the F1 and F2 keys, placed on the
front panel, on which there are 5 Led that indicate:
3
rd
red Led "ALARM 3":
3
rd
relay activation
2
nd
red Led "ALARM 2":
2
nd
relay activation
1
st
red Led "ALARM 1":
1
st
relay activation
Green Led "ON":
normal working condition
Yellow Led "FAULT":
the sensor should be faulty, disconnected, out of scale or expired.
NOTES ON THE DETECTED GAS
The above Gas value is on compliance with EN61779-1.
SE237EA
has a sensor that can detect
Ammonia
(NH
3
)
gas which is a toxic, colourless and with a characteristic
pungent smell,
lighter than air
, (
its density as to air is 0.6
). His
TWA
is 25ppm (
Time-Weighted Average
) and
STEL
is
35ppm (
Short Term Exposure Limit
). His LEL (
Lower Explosivity Limit
) is 15% v/v (volume). This gas is irritating to the eyes
and mucous membranes (respiratory and digestive tracts). Ammonia is used in industrial refrigeration applications.
It is also used as fertilizers (either as its salts), as a component in paints, for the production of plastics and poly-
mers, such as solvent or as household cleaners.
SE237EA-H
model is as previous, but it uses a sensor suitable for industry and polluted environments and with
presence of other toxic gases.
SE237EC-S
has a sensor that can detect
Carbon monoxide
(CO
) gas which is a poisonous, colourless, odour-
less, and tasteless. CO is
a little lighter than air
(
its density as to air is 0.97
) and his LEL (
Lower Explosive Limit
) is
10.9%v/v (%volume). His
TWA is 25 ppm
(
Time-Weighted Average
) and
STEL is 50 ppm
(
Short Term Exposure Limit
).
CO is produced by incomplete burning of carbon-based fuels, including gas, oil, wood and coal. Carbon-based
fuels are safe to use. It is only when the fuel does not burn properly that excess CO is produced, which is poison-
ous. When CO enters the body, it prevents the blood from bringing oxygen to cells, tissues, and organs.
SE237EC-H
model is as previous, but it uses a sensor suitable for industry and polluted environments and with
presence of other toxic gases.
SE237ES
has a sensor that can detect
Sulphur dioxide
(SO
2
)
(
also Sulphurous anhydride, Sulphurous oxide, Sulphur ox-
ide
) gas which is a toxic, colourless, with pungent odour,
heavier than air
(
its density as to air is 2.25
). His
TWA
(
Time-
Weighted Average
) is 2 ppm and
STEL
(
Short Term Exposure Limit
) is 5 ppm.
SO
2
is a strong irritant to eyes and respiratory system. Inhalation may cause pulmonary edema and prolonged ex-
posure can lead to death and when it combines with water forms H
2
S (Hydrogen sulphide).
SE237EH
has a sensor that can detect
Hydrogen sulphide (H
2
S)
(
synonymous with hydrogen sulphide
) gas which is a
toxic, flammable, colourless, with a characteristic odour of rotten eggs,
heavier than air
(
its density as to air is 1.19
).
His
TWA
is 5ppm (
Time-Weighted Average
) and
STEL
is 10 ppm (
Short Term Exposure Limit
). His
LEL
(
Lower Explosive Limit
)
is 4% volume. The H
2
S smell is perceived at concentrations above 0.2 ppm, to low levels (50÷100 ppm) already
produces irritation to the eyes and throat, cough, fast breathing and training of fluid in the respiratory tract. This
gas, over 150 ppm, acts on the olfactory nerve, making it impossible for the perception of its odour, and higher
concentrations can cause unconsciousness within a few minutes and can lead to death.
SE237EHCN
has a sensor that can detect
Hydrogen cyanide (HCN)
(synonymous with Hydrocyanic acid, Prussic acid)
gas which is a toxic, extremely poisonous gas, colourless, with has an almond-like odour,
a little lighter than air
(
its density as to air is 0.94
). His
TWA
(
Time-Weighted Average
) is
4.7
ppm and
STEL
(
Short Term Exposure Limit
) is
10 ppm
.
The
HCN
is a strong irritant to eyes and respiratory system. Inhalation may cause effects on the cellular respira-
tion, resulting in convulsions and unconsciousness. Exposure to 300ppm for 2 minutes may result in death.
