ISO 51900:2009 applies to the minimum requirements for dosimetry needed to conduct research on the effect of radiation on food and agricultural products. Such research includes establishment of the quantitative relationship between absorbed dose and the relevant effects in these products. ISO 51900:2009 also describes the overall requirement for dosimetry in such research, and in reporting of the results. It is necessary that dosimetry be considered as an integral part of the experiment. ISO 51900:2009 applies to research conducted using the following types of ionizing radiation: gamma radiation, X-ray (bremsstrahlung), and electron beams. The purpose of ISO 51900:2009 is to ensure that the radiation source and experimental methodology are chosen such that the results of the experiment will be useful and understandable to other scientists and regulatory agencies. ISO 51900:2009 describes dosimetry requirements for establishing the experimental method and for routine experiments; however, ISO 51900:2009 is not intended to limit the flexibility of the experimenter in the determination of the experimental methodology. ISO 51900:2009 includes tutorial information in the form of notes. ISO 51900:2009 does not include dosimetry requirements for installation qualification or operational qualification of the irradiation facility.