Table des Matières
Publicité
Les langues disponibles
Les langues disponibles
IST-293.IM01.01/B
EN
DESCRIPTION
The TS293I series is a combustible gas detector with a NDIR – Non dispersive Infrared Sensor, calibrated up to
100% LEL to different gases and find their best application in centralized alarm systems for laboratories, manufac-
turing industries and environments to be protected from possible leakage of flammable gases or vapours.
The instruments is flameproof certified and comprise of an enclosure in which the electronic circuit and the termi-
nals are mounted and a downward facing cylindrical sensor housing with inside a replaceable "Cartridge Sensor".
The instrument has a 4÷20mA linear output (S) with %LEL (Lower Explosive Limit) F.S. of detected gas. This output is
connectable to a remote Gas Control Unit as listed in
Test and Calibration routine protected by a code and 3 LED shows the working conditions:
Red LED "ALARM":
Green LED "ON":
Yellow LED "FAULT":
NOTES ON THE AVAILABLE MODELS
The above LEL gas values are on compliance with European standards.
TS293IM (CH
) is calibrated to detect Methane (F.S. 100%LIE), a gas lighter than air. Its density as to air is 0.55 and
4
its LEL (Lower Explosive Limit) is 4.4% volume.
TS293IG (LPG) (Liquefied Petroleum Gas) is calibrated to detect LPG (F.S. 100%LIE), a gas heavier than air and con-
sists of a mixture of 20÷30% Propane (C
Butane' is 2.05. The LEL is 1.7% volume for Propane and 1.4% volume for Butane. Standard calibration to LPG is
carried out for Butane gas.
TS593IB (Unleaded Gasoline/Petrol) is calibrated to detect Gasoline (F.S. 100%LIE), vapours heavier than air and
highly flammable. Its density as to air about 2.5÷3 and its LEL (Lower Explosive Limit) is about 1.4% volume.
TS293IX can be calibrated to detect various gases listed in
code of the replacement Sensor Cartridge
umn
6), and the density (average) relative to air
OPERATIONAL DESCRIPTION
The infrared sensor (NDIR) is compensated for temperature changes and can be used in polluted environments
without a significant degradation of performance and also works in environments with oxygen deficiency. The cali-
bration is performed for the specific gas, but it may also detect other flammable gases, if present in the same envi-
ronment. It is insensitive to all types of toxic vapours and also in areas with deficiency of oxygen.
The operational mode of the NDIR sensor is based on the physical principle that certain types of gases absorb
certain wavelengths of infrared energy.
The sensor is double: the first, defined as active, has an optical filter for the specific gas to be detected, while the
second, called "reference" has a filter with a different wavelength and provides the "Zero" value. The signal differ-
ence between the two sensors provides the value of the gas concentration. The advantage of this technique is that
the sensor is selective only for hydrocarbon gases and allows compensating the sensitivity drift of the detector over
time. The only cause of interference can be given by the presence of water vapour, which absorbs infrared.
Note that the LED are not visible when the enclosure is closed.
Preheating (60 seconds): when powered, the sensor needs a time of preliminary heating of about 60 seconds.
During this period the yellow LED "FAULT" flashes. After this period, the yellow LED light off, the green LED "ON" il-
luminates to indicate normal operation. Then the sensor is able to detect the gas, but it reaches the optimum stabil-
ity conditions after about an hour of continuous operation.
Normal operation: the green LED "ON" should be light on.
Alarm: when Gas concentration attains 20% LEL the red LED "ALARM" illuminates (if it is enabled with dip-switch).
Faults: the Yellow LED (FAULT) illuminates and the "S" output falls down to 0mA. (See below).
Yellow LED illuminates each 4 seconds (with green LED activate): this happens when the "Cartridge Sensor" has
overcome its period of life (about 5 years) and its correct operation is no longer guaranteed. The detector keeps on
operating normally but it is necessary to replace, as soon as possible, the "Cartridge Sensor" with a new one. The
type to be required is listed
Yellow LED activate, green LED off (0mA output signal): this signal different kind of faults. 1) The Dip Switch set
up is wrong, please verify
communication or uncorrected) please replace with new one. 3) If a new "Cartridge Sensor" is installed, or it is not
correctly connected or a not compatible one is mounted. Please check the cartridge connections and compatibility
(see on page
1) these checks are made connecting and disconnecting the device. If the condition does not change,
please replace the unit and/or send it back to the supplier to repair.
Yellow and green LED activates (0mA output signal): this happens when the "Cartridge Sensor" is not working. First
try to perform the procedure of "ZERO" as described in the section "Test and Calibration > Zero adjust" then disconnect
and connect the unit, finally try to replace a new "Cartridge Sensor". If the condition is not change, please replace the
unit and/or send it back to the supplier to repair.
All LED activates (>24mA output signal): this happens when the "Cartridge Sensor" is not working or gas concentra-
tion is out of scale (higher than 100% LEL) If there are not any gas leaks and the condition is not change, please
replace the unit and/or send it back to the supplier to repair.
TECNOCONTROL S.r.l. - Via Miglioli 47 SEGRATE ( MI )ITALY
Istruzione / User's Manual / Manuel d'utilisation
20% LEL alarm indication
normal working condition
the sensor should be faulty, disconnected, out of scale or expired.
H
) and 80÷70% Butane (C
3
8
(Column
(Column
on page
1. The replacement procedure is described in the attached manual.
2). 2) The "Cartridge Sensor" is not working, (sensor fault or its connection, no
(see Table
Table
1. On the Printed Circuit Board, F1 and F2 key using for
H
). Propane density as to air is 1.56 while
4
10
Table 3 on column
2), the Measurement range
7).
Tel. +39 02 26922890 - Fax +39 02 2133734
1, which also indicate the relative
(Column
3), its LIE in volume%
Pag.5/12
(Col-
Publicité
Table des Matières
