Fig. 5. Visualization of the handheld alcohol breath analyzer.

a Photograph of the NDIR gas sensing system with the integrated meander-shaped IR emitter, including a multipath absorption cell for ethanol sensing (dark blue path) and a short absorption path for sensing of carbon dioxide (red path). The radiation from the IR emitter is reflected multiple times by the mirrors on both sides of the multipath absorption cell before it reaches the IR detector. b Photograph of the handheld breath alcohol analyzer prototype that enables contact-free alcohol breath sensing with immediate analysis results. The dimensions of the prototype are 6 cm × 3 cm × 16 cm