Product Details

IRM-AT Infrared Methane (CH4) Sensor Thermopile Detector Description
Alphasense CO2 and Methane infrared sensors are supplied in the industry standard miniature (20mm diameter) gas sensor housing.

Patented optics give the best signal to noise ratio of any 20mm diameter NDIR and universal linearisation constants allow easy implementation.

The on-board temperature sensor allows for software compensation, including ideal gas law correction.

Methane/ Hydrocarbons
The IRM-AT uses a dual thermopile detector for measuring Methane and other Hydrocarbons in non-explosive environments. The plastic housing limits use to non-Ex environments up to 2.5% Methane.

IRM-AT Infrared Methane (CH4) Sensor Thermopile Detector PERFORMANCE
Maximum Power Requirements	5.0 VDC, 60 mA max. (50% duty cycle source drive)
Minimum Operating Voltage	2.0 VDC, 20 mA max. (50% duty cycle source drive)
Source Drive Frequency	3 Hz typical, 50% duty cycle
Active/Reference Output in Air (peak-to-peak)	2 to 4 mV @ 3 Hz, 50% duty cycle
Typical active signal change for 2.5% CH4	5% drop (typical) @ 5 V, 3 Hz, 50% duty cycle
Typical active signal change for 100% CH4	30% drop (typical) @ 5 V, 3 Hz, 50% duty cycle
Response Time (t90)	<40 s @ 20℃ ambient
Warm-up Time	30 minutes @ 20℃, 5 VDC

IRM-AT Infrared Methane (CH4) Sensor Thermopile Detector LIFETIME
MTBF @ 5 VDC	> 3 years

IRM-AT Infrared Methane (CH4) Sensor Thermopile Detector KEY SPECIFICATIONS
Temperature Signal	Integral thermistor (NTC, R 25 = 100KΩ, ß= 3940 K)
Operating Temperature Range	-20℃ to +50℃(linear compensation from 0 to 40℃)
Storage Temperature Range	-40℃ to +75℃
Humidity Range	0 to 95% RH non-condensing

Range	0 - 2.5%	0 - 100%
Accuracy	<± 500 ppm	<± 1% vol
Resolution at zero	<200 ppm	<300 ppm
Resolution at range	<400 ppm	<2.5% vol
Zero repeatability	<± 500 ppm	<± 1,000 ppm
FS repeatability	<± 0.1% vol	<± 2% vol
Limit of detection	<500 ppm	<1,000 ppm

Span coefficient	0.074 - 0.094	1.1 - 1.3 @ 95%
Linearisation coefficient b	0.38	0.025
Linearisation coefficient c	0.98	0.553