Hi, I am trying to implement a low tech, quick "check" source for our radiation thermometers to ensure they are in good working order between calibrations again a calibrated black body radiation source. My idea was to use an integrating sphere with an incandescent lamp as a source. Then two signals would be tapped from the sphere via fibre optic leads and then fed into two radiation thermometers. One of the two radiation thermometers would be an offline unit which is known to be in good working order, unlike those used in production. I just want to know if this sounds feasible to you before I go drop a bit of cash having a go at it.