Abstract: Radiation measuring probe for contactless measurement of the surface temperature of an object, independent of the emissivity of the object. The probe includes a radiation receiver and a housing having interior surfaces defining an interior space. The radiation receiver is disposed in the interior space, thermally insulated with respect to the housing. The housing includes a shield which has a shield surface facing outwardly so as to be towards a surface of an object whose surface temperature is to be measured. The shield has an aperture opening into the shield surface, communicating with the interior space and through which thermal radiation emanating from the object impinges on the radiation receiver. The shield surface is blackened and configured to correspond to the contour of the surface of the object, and the interior surfaces of the housing are of low emissivity.

Abstract: For measuring the proportion or quantity of a component in a radiation-transparent mixture, a beam is passed through the mixture and subsequently split by a beam splitter into a measuring beam and a reference beam. The measuring beam is passed through a narrow-band interference filter which has a transmitting wavelength that corresponds to a discrete absorption wavelength of the component. This filter is oscillated in a range of oscillation which traverses the absorption maximum. The reference beam is passed through a narrow-band interference filter which has a transmitting wavelength that differs from the absorption wavelength of the component. Subsequently, the radiation intensities of the measuring beam and the reference beam are separately detected and their difference is formed. This difference is a function of the proportion or quantity of the component.