Abstract: A gas sensor (2) distinguishes between a target gas and a contaminant and includes a light source (8), a measurement volume (4), a detector (22), and an adaptable filter system (20) with a first optical filter and a second optical filter. The filter system switches between a first composite state, with both filters in a reference state, a second composite state, with the first filter in a first reference state and the second filter in a second measurement state, a third composite state with the first filter in a first measurement state and the second filter in a second reference state, and a fourth composite state, with both filters in a measurement state. The gas sensor detects a target gas and makes a determination as to a presence of the contaminant by comparing the respective detector signals, generated during at least three of the composite states, with each other.

Abstract: A gas sensor (2) distinguishes between a target gas and a contaminant and includes a light source (8), a measurement volume (4), a detector (22), and an adaptable filter system (20) with a first optical filter and a second optical filter. The filter system switches between a first composite state, with both filters in a reference state, a second composite state, with the first filter in a first reference state and the second filter in a second measurement state, a third composite state with the first filter in a first measurement state and the second filter in a second reference state, and a fourth composite state, with both filters in a measurement state. The gas sensor detects a target gas and makes a determination as to a presence of the contaminant by comparing the respective detector signals, generated during at least three of the composite states, with each other.

Abstract: A device for recognising a container by means of a marking provided on its surface, comprising a camera and light emission means (1, 2, 3) arranged for imaging the marking (4) on the container (5). The means is connected to a processor adapted for recognition, based on a camera-recorded image of the marking, of distinctive features related to the container. To ensure that the image has the quality required for recognition of the container, the means consists of one camera (1) and two light sources (2, 3), the said light sources being positioned in such manner, either on the same or on each side of the camera, that light emitted from the respective light sources falls in from a different direction relative to the marking, thereby allowing the camera to take two images of the marking using light emitted successively from the respective light source.