ISO 9847:1992, Solar energy -- Calibration of field pyranometers by comparison to a reference pyranometer

Specifies two preferred methods: the outdoor calibration (with the pyranometer in a horizontal position, in a tilted position, or at normal incidence) and the indoor calibration (using an integrating sphere with shaded or unshaded lamp, or at normal incidence). Applicable to most types of field pyranometers regardless of the type of radiation receptor employed.