Evidenzer is an IR-based evidence sampling instrument used in the legal system in several countries. The instrument comes in two different versions, Evidenzer Classic and Evidenzer Mobile. Classic does not have a keyboard or screen and is therefore connected to a personal computer with sampling software that displays the measurement result. Mobile has a built-in keyboard, screen, and printer for control and reading, but can also be used with a personal computer. The Evidenzer models are robust, designed to withstand outdoor environments with varying temperature conditions and to be moved between different positions such as cars, buses, boats, and helicopters. Both instruments are based on infrared (IR) technology, which is a very specific method for analyzing the impact of volatile substances, known as hydrocarbons, in exhaled air. The measurement values have high selectivity, i.e. the ability to determine which substance is influencing. By measuring the absorption of infrared light at several different wavelengths, it is possible to definitively establish that the influence truly comes from alcohol (ethanol).