Investigation of new universal measuring microscopes

1. The measurement errors of microscopes of the new system are at the same level as those of the UIM-21 and the Zeiss microscopes, with the exception of the error in measuring Dav of a thread gauge by means of the shadow method and the error in measuring the profile angle of a thread. 2. The larger error in measuring Dav and the profile angle as compared with similar existing instruments is due to the imperfections of certain units in the design. 3. The errors in measuring the diameters of smooth cylindrical gauges by the shadow projection and axial cross-section methods are considerably smaller than those obtained from the formulas of the manufacturing plant. 4. The manufacturing plant should indicate in the instrument's operating instructions the error in measuring a plane angle and provide a formula for the errors in measuring profile angles of thread gauges. 5. The utilization of wax screens in the sighting and display devices has not reduced the precision of the instruments, but at the same time has made them more convenient in work and tends to reduce the fatigue of the tester, thus raising the productivity of his labor. 6. The screens can be used for sighting not only in the shadow projection method, but also in the axial cross-section method. 7. Testing of the UIM-23 and UIM-24 instruments has shown that only in measuring the mean diameter of threads by the shadow projection method do the instrumental, technological, and adjustment deficiencies of these instruments have a most pronounced effect on the precision of their readings and the measurement error. Therefore, in drafting standards or procedure instructions for testing these instruments it is necessary to specify requirements for measuring the Dav of thread gauges by means of the shadow method.