The uncertainty of sound-source sound power determined by an intensity scanning method depends on the one hand on several measurement parameters such as scanning speed, integration time, density of scanning pattern paths, measurement equipment quality, and on the other hand, on the sound field quality having met under the actual in situ measurement conditions. In order to guarantee certain limits for the measurement uncertainties, it is necessary to adjust the measurement parameters to the actual specific conditions for the sound field under test. In the past (see ISO 9614-1) this adjustment was carried out with success by first determining certain indicators describing the actual sound field situation numerically and using the indicators together with relevant criteria in order to check the initially chosen measurement parameters in respect to the given uncertainty limits. At present, an international standard for a relevant scanning precision method (ISO 9614-3) is in preparation. Thereby, adequate indicators and criteria are in discussion worldwide. By an extensive measurement program carried out under well-defined laboratory conditions, and on machines in situ completed by theoretical investigations, certain proposals result that are relevant for the new standard, which will be presented in the paper.