INTRODUCTION

This test procedure is used to measure the cladding (outside) diameter of an optical fiber using a laser-based instrument. It is used on-line in the fiber drawing process prior. to the application of the protective buffer coating(s). It is also used off-line as a quality inspection method. In this application, it is normally used instead of FOTP-45.

Control of the cladding diameter is required to assure the performance of the fiber in cabling, connectorization and splicing. Uniformity of the cladding diameter along the length is also required.