Reflectance measuring device

Abstract

A measuring device, designed as a hand-held device, is disclosed, having a housing, an optical measuring head movably arranged in the housing for charging a test object with measuring light and for collecting light reflected by the test object, an opto-electric converter for converting the collected light into electrical signals, a computer processing the electrical signals and controlling the device, a display for displaying the measurement values obtained from the processing of the electrical signals and operating members working with the computer for controlling the device functions. Upon a triggering of the measuring process, the measuring head is moved, by a motor controller by a computer, out of a rest position into a measuring position and back into the rest position. A calibrating position is provided, in the housing, into which the measuring head can be moved and in which a calibration test object is disposed. The computer measures the calibration test object and generates calibration measurement values. Reference values corresponding to the calibration measurement values are stored in the computer. The computer performs calibration of the device by using calibration measurement values and the stored reference values. An automatic measurement of the calibration test objects in accordance with a predetermined program and a corresponding calibration or checking processes of the device can be performed. An accurate measurement of the calibration test objects is achieved as the calibration test objects are always available and cannot be confused with calibration test objects of other measuring devices.