Model WES-1000D electro-hydraulic universal testing machine is a digital display univer- sal testing machine which is developed and manufaetered completely by Jinan Shijin Group self.

The digital readout instrument of the round inductosyn is a precise angle measuring instrument, for attaining highly angle measuring accuracy, must to the round inductosyn position proceeds the precise adjustment.

The operational principle of the digital readout instrument angle measurement is introduced based on the round inductosyn.

The Recognition of Digital Indicator in High-voltage Transformer Substation;

The subdivision and identifying direction problem of raster data display instrument is proposed by studying the principle of raster measuring.

The Principle and design method of double coordinates machines tool digital display instrument adopting combination of digital display technique with computing technique are discussed in detail .

The uncertainty evaluation of measuring results about indicator error of digital dial gauge 0~25 mm was analyzed in this article,those indicated that it was feasible using TWIN-CHECK1200 length measuring machine as calibration tools.