A non-dispersive infrared measuring arrangement for a multigas analyzer is described having a radiation source (10), a measuring chamber (20), a beam splitter (3), at least a first and a second detector unit (21, 22) both with at least two detectors (1a, 1b; 2a, 2b); and optical filters in radiation beam portions ending in said detectors. The detector units receive the reflected beam portions (R.sub.R) and the transmitted beam portion (R.sub.T). Both the first and second detector units (21, 22) have: at least one measuring detectors (1a, 1b) provided with an optical measurement filter (5a, 5b); and at least one reference detectors (2a, 2b) provided with an optical reference filter (6a, 6b). Alternatively, the first detector unit (21) has at least two measuring detectors (1a, 1b) each provided with an optical measurement filter (5a, 5b), and the second detector unit (22) has at least two reference detectors (2a, 2b) each provided with an optical reference filter (6a, 6b). The first detector in said first detector unit and said second detector in said second detector unit are positioned to constitute a first independent single path analyzer channel (11), and said second detector in said first detector unit and said first detector in said second detector unit are positioned to constitute a second independent single path analyzer channel (12).