Semiconductor Detectors

They have been introduced in the market in 1968 and use a sintered tin dioxide n-type semiconductor sensor. The semiconductor temperature is set to 200°C to increase the sensitivity to the gas and to reduce the influence of ambient temperature. When the semiconductor meets the gas it reacts reducing its resistance. This type of detectors is available in many models for various gas types, requires little maintanance and is normally guaranteed to work well for ten years. These detectors have great sensibility and don't react badly to high concentrations or to silicones.

Advantages

• great sensibility
• can not be affected by silicone fumes
• sensibility can not be affected by high concentrations
• require minimum maintanance
• normally guaranteed to work well for 10 years

Available Models

Explosion Proof Execution - Ex-d - ATEX certified

Gas	Model	Nominal Range	Analog Output	Relay Output	Alarm Threshold
ammonia	EV473A	20-1,000 ppm	X	X	2
ammonia	EV474A	20-1,000 ppm	X
methane	EV473M	0-20% LIE	X	X	2
methane	EV474M	0-20% LIE	X
carbon monoxide	EV551CO	0-200 ppm		X	2

TECHNICAL DATA

• power supply : 12 - 24Vcc (+/-15%)
• power : 1W max
• nominal range : see table
• analog output : 0-5V
• relay output with 2 preset thresholds (adjustable) to 10% and 20% LIE
• temperature : -10 +40 °C
• umidity : 0 - 95%
• ambient pressure limit (+/-20%)
• alarm delay time : 2-5 sec.
• time of initial stabilization > 3 min
• vibration resistance: 250 Hz/mm
• shock resistance: 100gr
• sensor life: 10-12 years
• aluminium alloy explosion proof case
• explosion protection: 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
• cable entry: 3/4" - UNI 6125 - ISO R7 - BS 21

Execution IP65

Gas	Model	Nominal Range	Analog Output	Relay Output	Alarm Threshold
methane	EV552M	0-20% LIE	X
methane	EV553M	0-20% LIE	X	X	2
carbon monoxide	EV556CO	0-200 ppm		X	2

TECHNICAL DATA

• power supply : 12 - 24Vcc (+/-15%)
• power : 1W max
• nominal range : see table
• analog output : 0-5V
• relay output with 2 preset thresholds (adjustable) to 10% and 20% LIE
• temperature : -10 +50 °C
• umidity : 0 - 95%
• ambient pressure limit (+/-20%)
• alarm delay time : 2-5 sec.
• time of initial stabilization > 3 min
• vibration resistance: 250 Hz/mm
• shock resistance: 100gr
• sensor life: 10-12 years
• polycarbonate case
• IP rating: IP65
• construction in accordance with standards: EN50054 - EN50057
• cable entry: 1/2" - UNI 6125 - ISO R7 - BS 21