BS EN 61745 discusses the end-face image analysis procedure for the calibration of optical fibre geometry test sets. End-face image analysis procedure for the calibration of optical fibre geometry test sets is the comparison of measurement values delivered by a device under test with those of a calibrated standard of known accuracy. BS EN 61745 describes the calibration of test sets that perform end-face image analysis, also known as "near-field" or "grey-scale" analysis. The principles, however, can be applied to test sets of a different type.
The procedures outlined in BS EN 61745 are performed by calibration laboratories and by the manufacturers or users of geometry test sets, for the purpose of calibrating geometry test sets and for evaluating the uncertainties in measurements made on calibrated test sets.
Note: The calibration of fibre coating or cable measurement test sets is not covered by BS EN 61745.
BS EN 61745 on the End-face image analysis procedure is useful for:
In the research and production environments, there exists a range of test methods for characterizing the geometry of optical fibres. Furthermore, each test method may determine one or more of the many parameters required for complete geometrical characterization. BS EN 61745 describes the calibration of test sets that perform end-face image analysis, also known as "near-field" or "grey-scale" analysis. The principles, however, may be applied to test sets of a different type. The geometrical parameters measured by the types of test sets consist of the cladding (reference surface) diameter, cladding non-circularity and core/cladding concentricity error.
The calibration procedure comprises the magnification, or scaling factor, of the imaging system is calibrated. This is a similar process to conventional calibration methods for optical microscopes, except that, in this case, a two-dimensional calibration is required. A correction offset is determined. This offset is required to correct for systematic effects such as diffraction at the fibre edge, differences between the way the calibration artefact is calibrated and the method of measurement in the test set, and distortion of the image of the fibre edge by camera sampling. Using BS EN 61745 you can describe the calibration of test sets that perform end-face image analysis, also known as "near-field" or "grey-scale" analysis.
BS EN 61745:2017 supersedes BS IEC 61745:1998. BS EN 61745:2017 includes some technical changes with respect to BS IEC 61745:1998. These include:
EN 61745:2017
IEC 61745:2017