本文报道一种高灵敏度分束干涉型ＬＣＤ盒间隙厚度测量仪（以下简称测厚仪），并重点介绍其两项关键技术：干涉条纹级次的彩色识别法和光楔干涉定标法。要精确测量液晶盒间隙厚度，必须准确测定基准和测量这两组干涉条纹间的距离，因而必须准确识别干涉条纹的级次。强度识别法的测量精度易受随机噪声的影响。本文提出条纹级次的彩色识别法，利用这种方法，测量精度可以大幅度提高。定标是测厚仪的另一关键技术。本文提出独特的光楔干涉定标法。文中给出了光楔干涉法定标精度的理论估算，同时制成一光楔并应用于高精度测厚仪的实际定标 This paper reports a high sensitivity beam splitter interferometer LCD gap thickness measuring instrument (hereinafter referred to as thickness gauge), and focuses on its two key technologies: interference fringe level color identification method and optical wedge interference calibration method. To accurately measure the cell gap thickness, you must accurately measure the reference and measure the distance between these two sets of interference fringes, which must accurately identify the interference fringe level. The accuracy of intensity recognition method is sensitive to random noise. In this paper, the fringe level color identification method is proposed. With this method, the measurement accuracy can be greatly improved. Calibration is another key gauge of thickness. This paper presents a unique optical wedge interference calibration method. In this paper, the theoretical estimation of the precision of optical wedge interferometry is given, and an optical wedge is made and applied to the actual calibration of high precision thickness gauge