In this article,we analyze the contact measurement and non-contact measurement for taper thread plug gauge,and the think that using CCD vidicon to detect and measure taper thread plug gauge is a new non-contact measurement method.

On account of the particularity of evaporator liquid level measurement,namely,on the basis of the following properties of the material——hypothermia,high voltage,deep-etching,easy-fouling and azeotropic mixture,this article proposes a non-contact measurement.

Research on non-contact measurement methods for the dimension of inner diameter based on the principle of optical triangulation;

On the basis of electric eddy current's characteristic that non-contact measurement,we measure boring cutter's radial move accurately with two-point method,to improve the machining precision.

This instrument can realize a quick and non-contact measurement with high accuracy.

In this paper, a non contact measurement apparatus by means of matrix CCD as the photoelectric sensor for the geometrical sizes of common cylindrical exterior thread is developed.

Based on the contact type measuring machine for bent tube, the probe, which is improved by using laser and CCD, can be used to achieve the non contact measurement of a bent tube.

Referring to the contact type bent tube measuring machine, a probe, which is improved by the use of two laser diodes and two photodiodes, is used to achieve the non contact measurement of the bent tube.