OCIEngine ethanol sensor

Miniaturized infrared spectroscopy sensors dedicated to ethanol measurement

OCIEngine is an infrared spectrometer that measures Volatile Organic Compounds (VOC) in the air. It is specific to analyse a molecule of interest, such as ethyl alcohol.

The measuring chamber of the sensor is crossed by infrared radiation. When the air is introduced into this chamber, the molecules of interest absorb a part of the radiation, which reduces the intensity of the optical signal. The concentration of the gas can therefore be deduced according to the Beer-Lambert’s physical law.

Technical specifications

Alcohol detection

Unit of measurement Breath alcohol content (BrAC) in exhaled air: µg/L
Measurement range From 50 to 4000 µg/L
50 µg/L corresponds to the detection limit of the measuring cell
Measurement accuracy
(max error)
– ambient temperature: 23°C (± 3°C)
– wet air inlet (>95% RH, 23°C): ethanol gas
– flow rate: ~ 0,25 L/min
± 20 µg/L @ 100 µg/L
± 40 µg/L @ 400 µg/L

Sampling characteristics

Test duration 4000 ms minimum
Air inlet  Minimal relative pressure to activate alcohol measurement: 0.3 mbar
Minimal relative pressure during the test to have alcohol measurement valid: 0.2 mbar
Maximal relative pressure at measuring cell inlet port: 10 millibars
Flow rate range From 0,1 to 1,5 L/min
Sampling period 125 ms

Electrical conditions

Supply voltage 3,7 VDC min
4,2 VDC max
Input current 1,5 A max
Communication interface RS232 protocol (other on request)
Solder pad connection (recommended cable sections : ≤0.13 mm² AWG ≥ 26)

Environnemental conditions

Operating conditions From 0°C to 50°C
Storage From -10°C to 70°C
Typical starting time (pre-heating phase) depending on the ambient temperature: @ 0°C: 160 s. / @ 10°C: 80 s. / @ 20°C: 60 s. / @ 40°C: 40 s.

Package information

Dimensions and weight 21 x 21 x 80 mm, 17g
External plastic casing ABS PC-UL94V0
Fixing parts 3 apertures (Ø 1.6 mm) compatible with self-tapping screws
(1.8 mm recommended) to fix OCIEngine

Sensor architecture

Mechanical drawings