IST-293.IM01.01
Istruzione / User’s Manual / Manuel d’utilisation
Pag.4/10
TECNOCONTROL s.p.a:Via Miglioli 97 SEGRATE ( MI )ITALY
Tel. +39 02 26922890 - Fax +39 02 2133734
“
Calibrazione
” premendo F2. Se la condizione di errore persiste, provare a spegnere e accendere l’apparecchio, op-
pure sostituire la “
Cartuccia Sensore
”
.
NOTA
: E’ possibile uscire in qualsiasi momento dalla funzione di calibrazione premendo contemporaneamente i
tasti F1 e F2, in questo modo il sistema torna in funzionamento normale mantenendo la precedente taratura.
“VERIFICA” (
Non serve Codice
)
:
serve per controllare la corretta risposta del rilevatore al gas e può essere esegui-
ta prima e dopo la “
Calibrazione
” o l’installazione, ma va eseguita soprattutto durante le manutenzioni periodiche.
NOTA IMPORTANTE
: utilizzare in base al modello, la miscela di gas sopra indicata.
Infilare il TC011 (
o il TC014
) sul portasensore, regolare il riduttore della bombola in modo che il flussometro indichi
da 0,3 a 0,5 l/min (
vedi Fig.3
).
Controllare, che con i puntali del voltmetro sui Test-Point “
TP1 e TP2
”, (
vedi Fig.2
) si
raggiunga il valore in
mV
indicato in
Tabella 3-Colonna 6
[
ovvero che l’uscita in mA aumenti fino al valore indicato nella
Colonna 7
(±0,5mA) e la centrale, cui è collegato il rilevatore, indichi il valore in %LIE (± 3) indicato in
Colonna 8
].
Se il valore fosse diverso,
eseguire la “
Calibrazione
”. Terminata la “
Verifica
”, chiudere la bombola e togliere il TC011 (
o il TC014
). L’uscita, torne-
rà a 4 mA.
Esempio:
se si deve verificare un rilevatore TS293IG tarato per GPL (Butano), utilizzando una bombola con Buta-
no a 0,7%volume (=50%LIE) in Aria, l’uscita in mA dovrà essere circa 12 mA
(±0,5 mA)
(ovvero da 115 a 125 mV
misurati su “
TP1 e TP2
”).
EN
DESCRIPTION
The
TS293I
series is a gas detector able to detect combustible gases by employing a
NDIR – Non dispersive In-
frared Sensor
, calibrated up to 100% LEL to different gases and find their best application in centralized alarm
systems for laboratories, manufacturing industries and environments to be protected from possible leakage of gas.
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
100%LEL
(
Lower Explosive Limit
) FS of detected gas. This output
is connectable to a remote Gas Central Unit as listed in
Table 1
.
On the Printed Circuit Board, F1 and F2 key using
for Test and Calibration routine protected by a code and 3 LED shows the working conditions:
Red LED "ALARM":
20% LEL alarm indication.
(See Table 2
)
Green LED "ON":
normal working condition
Yellow LED "FAULT":
the sensor should be faulty, disconnected, out of scale or expired.
NOTES ON THE AVAILABLE MODELS
The above LEL gas values are on compliance with European standards.
TS293IM (CH
4
)
is calibrated to detect
Methane
, a gas lighter than air. Its density as to air is 0.55 and its LEL (
Lower
Explosive Limit
) is 4.4% volume.
TS293IG (LPG)
is calibrated to detect
LPG
(
Liquefied petroleum gas
), a gas heavier than air and consists of a mix-
ture of 20÷30% Propane (C
3
H
8
) and 80÷70% Butane (C
4
H
10
). Propane density as to air is 1.56 while 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.
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 LEDs are not visible when the enclosure is closed.
Preheating
: when powered, the sensor needs a time of preliminary heating of about 60 seconds. During this pe-
riod the yellow LED “
FAULT
” flashes. After this period, the yellow LED light off, the green LED “
ON
” illuminates to in-
dicate normal functioning. After this period the unit is able to detect gas even if it attains the optimum stability con-
ditions after about 20÷30 minutes continual functioning.
Normal operation
: the green LED “
ON
” should be light on.
Alarm
:
when Gas concentration attains
20% LEL
the red LED “
ALARM
”
illuminates (
only if it be activate by Dip-Switch
).
Faults
:
the Yellow LED (
FAULT
) illuminates and the "
S
" output falls down to 0mA. (
The different faults are listed below
).
Yellow LED illuminates each 3 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 not 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 in
Table 3
(2nd column)
. The replacement procedure is described in the attached manual.
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 (
see Table 2
).
2)
The “
Cartridge Sensor
” is not working, (sensor fault or its connection, no
