Feedback based gas sensing setup for ppb to ppm level sensing.

Sensing and quantification of gas at low concentrations is of paramount importance, especially with highly flammable and explosive gases such as hydrogen. Standard gas sensing setups have a limit of measuring ultra-low concentrations of few parts per billion unless the external gas cylinders are changed to ones with low concentrations. In this work, we describe a home-built resistance based gas sensing setup that can sense across a wide concentration range, from parts per billion to parts per million, accurately.