Abstract: An arrangement for recording an IR image of an object. The arrangement has a focal plane array (FPA) of IR detectors and an optic which images the object on the focal plane IR detector array. At least one temperature reference is arranged in the beam path of the focal IR detector array. At least one IR reference detector is assigned as a reference among the IR detector elements in this array. Each temperature reference is coordinated with at least one of the IR reference detector elements so that each of the IR reference detector elements is impinged upon by radiation deriving essentially solely from one of the temperature references. An IR detector reference output signal is intended to be produced for each temperature reference. Each IR reference output signal is intended to set an individual reference level for the output signals from the remaining IR detector elements in the IR detector array.

Abstract: An arrangement for calibration of at least one radiation-sensitive detector, comprising an aperture (90), at least one reference body (50, 60, 600) which emits radiation with a measurable intensity, at least one deflection member (160, 170, 620) which deflects radiation from the reference body, and at least one radiation-sensitive detector (30) which detects the radiation value and generates an output signal dependent on the detected radiation value. During reference measurement the deflection member is arranged to reproduce the aperture (90) on the reference body (50, 60, 600), and the deflection member (160, 170, 620) deflects the radiation such that the midpoint of the reproduction of the aperture (90) remains on substantially the same area of the surface of the reference body (50, 60, 600) during that time period in which the detector receives radiation which is transmitted from the reference body and which passes through the aperture (90).