一、前言国产S-1、S-2及SY-WG-4型高度表试验器是校验WG-2、WG-3等型号无线电高度表的专用标准仪器。它的量值准确与否直接影响无线电高度表的性能和飞机的飞行安全。二十多年来,很多单位都是以CCD-1型电长度测量仪作标准来校准高度表试验器当量高度。即以CCD-1型电长度测量仪作标准鉴相 I. Preface The homemade S-1, S-2 and SY-WG-4 altimeters are special standard instruments for calibrating the radio altimeters such as WG-2 and WG-3. Its magnitude or accuracy directly affects the performance of the radio altimeter and the flight safety of the aircraft. For more than 20 years, many units have adopted the CCD-1 type electric length gauge as a standard to calibrate the altimeter tester equivalent height. Namely CCD-1-type electric length measuring instrument for the phase Kam