Device and method for optical reflection measurement on coloured objects

摘要

The device is specified for optical reflection measurement on coloured objects and is designed in the form of a one-piece housing (1) containing a current source and having a measured value display area. The housing is provided with a measuring head (3) having a measuring aperture (2) in which are arranged photocells (4) directed to the measuring aperture (2), shielded against direct incidence of measuring light, and capable of being supplied with measuring light via the measuring aperture (2), these photocells being connected to an electronic measured value conversion and evaluation circuit. In order to improve devices of this type in such a way that the photocells (4) in the device and the electronics can be used both for the reference measurements and the actual measurements, and indeed with the proviso of not having always to use the previously common calibration standard, the device according to the invention is so designed that a closure plate (6), which can be set and reset again in front of the measuring aperture (2) of the measuring head (3), is arranged on the housing (1), the surface (7) of the said closure plate (6) on the measurement aperture side being designed as a uniformly applied white, grey or coloured reference measuring surface for the photocells (4) acting both for the measurement process on the object and for reference measurements. <IMAGE>