Method and gonioradiometer for the direction-dependent measurement of at least one lighting or radiometric characteristic variable of an optical radiation source installed in an object

A method for direction-dependent measurement of at least one lighting or radiometric characteristic quantity of an optical radiation source installed in an object, wherein the method comprises:

• arranging an object at or on a holding element, which is intended and configured to rotate the object about a first axis and about a second axis which is perpendicular to the first axis, the object being arranged on the holding element in such a way that a radiation centroid of the optical radiation source lies outside the origin of a first coordinate system formed by the first axis and the second axis,
• determining a position of the radiation centroid of the optical radiation source relative to the origin of the first coordinate system as a relative position,
• performing a gonioradiometric measurement which comprises rotation of the object about the two axes, the gonioradiometric measurement being carried out in the first coordinate system,
• direction-dependently recording a measurement quantity of the radiation source by the gonioradiometric measurement for a multiplicity of emission directions, wherein the emission directions which are defined in the first coordinate system are respectively assigned measured values of the measurement quantity,
• calculating the direction-dependent measurement quantity for the multiplicity of emission directions in a second coordinate system, wherein the radiation centroid of the optical radiation source lies at the origin of the second coordinate system, from direction-dependently recorded values of the measurement quantity which have been ascertained in the first coordinate system and the relative position,
• wherein the measurement quantity is the same as the characteristic quantity to be measured or the characteristic quantity to be measured is calculated from the measurement quantity.

A gonioradiometer for direction-dependent measurement of at least one lighting or radiometric characteristic quantity of an optical radiation source installed in an object, wherein the gonioradiometer comprises:

• a turntable comprising a rotation axis and a surface, the rotation axis of the turntable defining a first coordinate system having an origin and a spatial axis, wherein the origin of the first coordinate system is formed by a point of intersection of the surface of the turntable with the rotation axis, and wherein the spatial axis of the first coordinate system coincides with the rotation axis, and the turntable configured and arranged to receive an object in such a way that the radiation centroid of the optical radiation source is spaced apart from the origin of the first coordinate system,
• at least one sensor which is configured and intended to measure a measurement quantity of the radiation source,
• wherein the turntable and the at least one sensor are configured to carry out a gonioradiometric measurement, which comprises rotation of the object about the rotation axis of the turntable, in the first coordinate system, the measurement quantity being direction-dependently recorded by the gonioradiometric measurement for a multiplicity of emission directions, wherein the emission directions which are defined in the first coordinate system are respectively assigned measured values of the measurement quantity,
• a calculator which is intended and configured to calculate the measurement quantity for the multiplicity of emission directions in a second coordinate system, wherein the radiation centroid of the optical radiation source lies at the origin of the second coordinate system, from the position of the radiation centroid of the optical radiation source relative to the origin of the first coordinate system and from the direction-dependently recorded values of the measurement quantity which have been ascertained in the first coordinate system,
• the calculator furthermore being intended and configured to calculate the characteristic quantity to be measured from the measurement quantity, if the measurement quantity is not already the characteristic quantity to be measured.