Abstract:The development history of definition of metre was introduced in this paper, theenlightenment in which we got is: the definition so closely still was revised to make it better. Theoriginal definition and prescription such as the length definition of gauge block,of measuring method,ofmeasuring principle and of the estimationof measuring reliability etc. are continually being replaced bynewone

Abstract:Methods and characteristics of opto- electrical signal processing of heterodyneinterferometer are described and analysised in this paper. Their applying fields are showed. At the sametime a new opto-electrical processing method is introduced. With the new method the heterodyneinterferometer can not onlu be used to measure dynamically. but also reach to a high measurementtesolution.

Abstract:In this paper, the theory of cantilever 3D CMM is discussed in accordance with itsfeature,the compensation for the deformation of the horizontal beam is introduced. After studying thetrack of the probe, we present a calculating method for adjusting the horizontal beam in detail. Theresults of the design and adjustment of the horizontal beam do show that this approach is feasible.Furthermore,the machine has surpassed the same products in our country.

Abstract:The computational method of surface roughness parameters is introduced in this articleand the method is realised by Quick Basic.

Abstract:A precise mechanical product demands optimal performance, increasing reliability andbetter quality. If these are ensured by means of closer tolerance in the design phase, the considerableproblems in the production and assembly period will be brought. It is reasonable that thesecharacteristics should be met with in the tolerance as wide as possible. The method discussed in thispaper using statistical tolerance is a practical way.