Will the installation of the fibre adapter affect the calibration of the detector head?
Any light impinging onto a free beam detector or an integrating sphere will be reflected to some extent back towards the source. The calibration of the head was performed with no adapters installed. Thus, by mounting an adapter, there will be some affect on calibration since part of the back reflected light is reflected again by the adapter back towards the detector, thus increasing the amount of optical power impinging on the detector. The fibre adapter is manufactured with black anodized aluminium to minimize this effect.
Will the detector receive all of the (divergent) light emitting from the fibre?
When used with integrating spheres, the detector will receive all of the light emitted from the fibre since the sphere has a wider field of view than divergence of optical fibre.
This is not necessarily the case with free beam heads. Before deciding on the use of a fibre adapter with a free beam head, the user should ensure that the beam size and divergence will not overfill the detector. Also, when used with APC connectorized fibres, particular attention must be taken to this point since the beam also emits at a skewed angle.