Catalytic Detectors

In these detectors the sensor is made of a platinum coil covered with a special catalyzer. The coil temperature, during its work, is set to 400°C using a suitable current. The detector's operation is based on the principle of electro-catalysis. When the mixture of air and gas or combustible fumes meets the catalyzer, the temperature of the platinum coil increases, because of oxidation and the filament, having an high positive coefficient, increases its resistance proportionally to the gas concentration. To avoid that the ambient conditions ( temperature and humidity ) can seriously affect the measure, a second twin sensor, with the catalyzer inhibited, is used as a compensator in the measure circuit. So the twin sensor does not react to gas or fumes, but only to the ambient conditions ( temperature and humidity ), and so it compensates the measure sensor's errors.

Advantages

• immunity to temperature and humidity effects
• linear output signal
• rapid response
• good stability
• measure repeatibility
• quite selectivity to gas
  

Available Models

Explosion Proof Execution - EX-d - ATEX certified

Gas	Model	Nominal Range	Analog Output	Relay Output	Preset Treshols
ammonia	EV469A	20-20.000 ppm	X
methane	EV469M	0-20% LIE	X
ammonia	EV471A	20-20.000 ppm	X	X	2
methane	EV471M	0-20% LIE	X	X	2

TECHNICAL DATA

• power supply: 12 - 24Vcc (+/-15%)
• power: 1W max
• nominal range: see table
• analog output signal: 0 - 5V
• relay output with 2 preset thesholds
• temperature: -10 +40 °C
• humidity: 15 - 90%
• ambient pressure limit: +/-20%
• linearity: 0-5%
• long term output drift: < +/-10% segnale/month
• zero output drift: < 5% LIE/month
• operating time delay: >20 sec.
• response time: > 10 sec
• operating life: 2 years
• explosion proof aluminium alloy box
• execution: Ex d II C T6
• IP rating: IP65
• certification: CESI EX - 96.108 X/N
• construction in accordance with standards: EN50014 - EN50018-EN50020 - EN50054 - EN50057 - CEI 64-2
• quality approval: BS5750Pt3 - ISO9002 - EN29002
• cable entry: 3/4" - UNI 6125 - ISO R7 - BS 21

Esecuzione IP65

Gas	Model	Nominal Range	Analog Output	Relay Output	Preset Treshold
methane	EV554M	0-20% LIE	X
methane	EV555M	0-20% LIE	X	X	2

TECHNICAL DATA

• power supply: 12 - 24Vcc (+/-15%)
• power: 1W max
• nominal range: see table
• analog output signal: 0 - 5V
• relay output with 2 preset thesholds
• temperature: -10 +40 °C
• humidity: 15 - 90%
• ambient pressure limit: +/-20%
• linearity: 0-5%
• long term output drift: < +/-10% segnale/month
• zero output drift: < 5% LIE/month
• operating time delay: >20 sec.
• response time: > 10 sec
• operating life: 4-5 years
• case: polycarbonate plastic
• IP rating: IP65
• construction in accordance with standards: EN50054 - EN50057
• quality approval: BS5750Pt3 - ISO9002 - EN29002