COMPARATIVE ANALYSIS OF CHARACTERISTICS OF COMPARATORS OF FINITE LENGTH MEASURES

Abstract

The main part of production measurements are linear-angular measurements - in mechanical engineering their share reaches 90-95%. The basis for ensuring the uniformity of measurements of linear dimensions is plane-parallel gauge blocks (KMD). Such measures are metal bars with two strictly parallel planes and a certain size between them. Timely and accurate KMD calibration en-sures high measurement accuracy in production.Now in factories for the calibration of KMD, KMD comparators of various types and de-signs are widely used, namely: contact interferometers, opticators, optimometers, ultraoptimmeters, optical length meters, and other manual and automated instruments.Most of these instruments provide for the use of a single-point measurement scheme (one movable stylus), which does not provide the necessary long-term stability of the calibration results due to mechanical wear of the lower reference point, and does not take into account the deformation of the test gauge. To determine the main metrological characteristics of KMD, the nomenclature of which is regulated by international standard, introduced in Ukraine as DSTU ISO 3650: 2009, it is necessary to use a two-point scheme (differential measurement method with two moving probes), which is also recommended by this standard. According to this scheme, KMD calibrators of foreign production operate, namely: Feinmess EMP II, Mahr Precimar 826, Tesa UPC, Tesa UPD and others.After analyzing the range of KMD comparators available on the modern market, it was de-cided to use the Feinmess EMP II comparator to calibrate the KMD. The results of its operation during the one year made it possible to carry out a comparative analysis of the functional character-istics of modern KMD comparators and their metrological characteristics in terms of the stability and repeatability of the calibration results.