The role of calibration in the overall analytical procedure is discussed and the potential role of flow injection techniques are assessed. The factors affecting the dispersion obtained in a flow injection system are described and examples given of how control of the various factors can be exploited to produce manifolds for calibration purposes. Most of these examples concern atomic spectrometry methods for which there is considerable interest at present in developing extended range calibrations and flow injection versions of the standard additions method. Several examples of the latter are given.