Analyze and adjust the spatial straightness error of the measurement axis of the light meter verification device.
The light track of the light meter verification device is two parallel hollow tubes, each hollow tube includes 6 sections, each section is 1m long, and the head and tail of each hollow tube are fastened to the V-shaped groove of the base. The straightness error of the optical track is caused by the unavoidable height difference in the Z direction and the offset difference in the X direction, the diameter difference of each hollow tube, and the deflection caused by its own weight.
In the process of calibrating the luminometer in the experiment, the sled with the luminous intensity standard lamp (referred to as the standard lamp) and its adjustment device is installed on the light track to the position of each verification point. The line connecting the center point of the standard lamp movement and the center point of the photometric head of the luminometer under inspection constitutes the measurement axis, which is a spatial connection line, and the degree of deviation from the center line is the spatial straightness error of the measurement axis. The measurement of the axis space straightness error is based on the linearity error of the optical track, adding the deflection of the optical track caused by the weight of the sled, whether the center installation of the standard lamp and the optical head is stable and reliable, whether the movement and positioning of the sled is accurate and stable, etc. Comprehensively, it affects the accuracy of the light meter verification result more comprehensively and practically than the straightness error of the light track surface. Therefore, the method of measuring the straightness of the optical track cannot be used to detect the spatial degree of the measurement axis, and the measurement space straight line formed by the line connecting each center point of the standard lamp movement and the photometric center point should be detected.
First, adjust the surface of the first section of the light track to the level, install and fix a fixed sled on one end (in the actual verification, the luminous head of the light meter under inspection is installed on the sled), place the autocollimator on the fixed sled and adjust Its optical axis is located in the symmetrical middle of the optical track (two hollow circular tubes). Then place another movable sled (the standard light is installed on the sled in the actual verification) closer to the autocollimator, and place the reflector of the autocollimator on the sled. The autocollimator pitch method is used for detection, and the measurement axis diagram composed of the line connecting the center point of the optical head and the center points of the standard lamp movement is obtained, and the measurement axis diagram is analyzed, and then the Z direction and the X direction of the measurement axis are adjusted. The spatial straightness error is as small as possible.
