The performance of a high precision reducer determines the accuracy and efficiency of the
mechanical motion, particularly in the field of industrial robots. To meet the requirements of …

In industrial and laboratory-based laser systems there are complicated processes involved
in the positioning of various optical components and these processes are time consuming …

The structure of the x-ray emission lines of the Cu ${\rm {K}}{\alpha} _ {} $ complex has been
remeasured on a newly commissioned instrument, in a manner directly traceable to the …

An influence model of collimating lens aberrations in an autocollimation system based on
the ray-tracing method is established. With the ray-tracing method, this model can accurately …

A cube-corner is employed as a photoelectric autocollimator's reflector to extend the angle
measurement range and the corresponding algorithms are deduced. Experimental …

Here we present a new test of the equivalence principle designed to search for the possible
violation of gravitational parity using test bodies with different chiralities. The test bodies are …

Precision lattice spacing comparison measurements at the National Institute of Standards
and Technology (NIST) provide traceability of X-ray wavelength and powder diffraction …

Abbe error is the inherent systematic error in linear displacement measurement due to the
measuring axis being out of line with the moving axis. The resulting gap is called the Abbe …

The NIST silicon lattice comparator has been in service, in various forms, since the 1970s. It
is capable of measuring the difference in lattice spacing between specimens of high-quality …

Circular grating usually served as the angle displacement feedback element in a precision
turntable, and its measurement accuracy is very important. Installation errors always exist in …