Ultra-low power gas sensors

Non-dispersive infrared (“NDIR”) sensors are potentially low-cost (<$100), ultra low-power (<5 mW) sensors that are designed to monitor the concentration of various gases for an extended period of time, > 10 years, on a single battery charge. NDIR sensors are using proprietary mid-IR LED-receiver pairs that are tuned to the absorption spectrum of the gas of interest. This NDIR technology has applicability to a variety of NDIR gas sensors for mobile and stationary leak detection, air quality monitoring and industrial processing.

Sensors

Ultra-low-power Series 5 NDIR methane sensors developed at BAH

 Parameter Specification
Sensing Gas Methane (CH4)
Sensor Version BAH-5
Operating Principle Non-dispersive infrared (NDIR)
Voltage, source 3.0 – 3.5 Vdc; 3.3 Vdc typical
Average Current 1 mA, typical
Averge Power 3 mW, typical
Detection Range 0-100%LEL or 0-100% Methane volume
Methane Concentration Units %LEL (500 ppm)
Resolution 1%LEL
Warm-up Time 10 sec
Response Time (T90) 30 sec
Temperature Range -30C to 65C
Humidity Range 0 to 90% RH
Communications UART, logic levels on TX and RX
Dimensions 45 mm diameter X 38 mm height

The following figures show typical performance of a low-power compact methane sensor.

Sensor_Graph1

Response of the sensor to change of the methane concentration in air.

Sensor_Graph2

Dependence of the optical absorption signal on the methane concentration.