EW146691_en - rev. A
Gas Detectors
–
UR.21.P
02/04/2020
Gas detection systems for car parks and tunnels
2/8
Technical Characteristics
Sensor type
Catalytic, Infrared, or
Semiconductor
Electrochemical Cell or
Semiconductor
Detectable Gas
(see available models)
Explosive Gases
(1)
Toxic Gases (e.g.: CO)
Power Supply
10÷28Vdc
10÷28Vdc
Maximum Power Consumption
(@ 28Vdc with 4÷20mA with s.c. output)
2,4W
(4W with UZR20.4)
1.2W
(2,8W with UZR20.4)
Measuring range
0÷100% LEL
(2)
0÷500 ppm
Precision (Catalytic, E.C., NDIR)
5% of Full Scale,
10% readout
Precision (Semiconductor)
10% of Full Scale (on calibration point)
Repeatability
5% of Full Scale,
10% readout
Measurement Resolution (Sensivity)
1% LEL
5 ppm
Microprocessor Resolution
4096 points (12 bit A/D Converter)
Digital Filter system
Kalman Filter and zero drift compensation
Watch dog
External, acting on the whole Safety Chain
Warm-up Time
< 2 minutes after every power on
Stabilization Time
2 hours from first power on
Response Time (Max)
< 20s (T50), < 60s (T90)
Average Sensor Life (in Air)
255 weeks
255 weeks
Output 4÷20mA signal type:
Proportional Output
(default)
Step Output
(1 o 2 thresholds application)
Settable reference of 4÷20mA
signal
- 4mA = 0% LEL; 0 ppm
- 20mA = 100% LEL; 500 ppm
- 0mA = no Alarm
- 10mA = 1
st
Threshold Alarm
- 20mA = 2
nd
Threshold Alarm
With jumpers (reference to negative or positive
of power supply)
Load Resistance of 4
…20mA output
(with generator limited to 24mA)
Minimum
0
@ 28Vdc
Maximum
300
@ 10Vdc
Operation and storage conditions:
Environment Temperature (°C)
-
Operating
-
Storage
-20
50 or -40 ÷ 70 (Extended Range)
-20
70
Relative Umidity (%UR) without condens.
- Operating
-
Storage
15
90
45
75
Operating Pressure (KPa)
80
120
Air Speed (m/s)
6
Optical Signalling
Red LED visible inside the housing
Dimensions and Weight
See dedicated paragraph
CE Conformity
EMC Directives / Standards
LVD Directives / Standards
Product Standard
EMC 2014/30/EU / EN50270 / EN 61326-1
Not applicable
EN60079-29-1
Note
(1)
:
Detectors using Catalytic Sensing Elements are sensitive to all Flammable Gases, with different sensitivities and responses related
to Methane Gas (see Tables contained in the Service Terminal Manuals), through which these relative responses can be inserted in the
Detector.
Note
(2)
:
When Detector detects a very high gradient of increasing concentration, and the full-scale value of 20% is exceeded, power is
removed from the sensing element and the out-of-range (fault condition for overrange) is declared respectively with:
−
the 4÷20mA output which is set at 22mA;
−
fault relay output activated (relay energized or not depending on the selection made);
−
the status LED visible from outside fixed on with an OFF flash of 0.5s every 5s
−
display (if present), explicitly declares the need for a recalibration.
After such a condition occurs:
−
make sure the area is free of explosive mixtures;
−
turn off and turn on the detector to allow the sensing element to be powered and wait at least an hour to allow thermal stabilization.
Only entering the calibration procedure can bring the detector to exit the overrange fault state.
As with all other operational contexts:
−
if the recalibration procedure is successful, it can bring the detector into normal operating status;
−
if the recalibration procedure is not successful, the detector is simply declared faulty.