Validation of a label dosimeter with regard to dose assurance in critical applications as quarantine control

A 'label dosimeter' (dose-threshold indicator) for dose ranges of insect disinfestation became commercially available only recently. It was studied for dosimetric (metrological) properties elsewhere. The fundamental problem of its application in practice is the relation between the dose observed at a reference position and the critical minimum dose achieved in a consignment. For this reason several irradiation geometries (relations between the arrangement of the goods during irradiation and the type of the radiation source, gamma, electrons, X-rays) were studied. The observed dose distributions revealed the difficulty that for any such geometry a 'label dosimeter' with a specific but differing threshold dose-value must be utilized in order to guarantee the adherence to the required minimum dose value. The 'label dosimeter' must be placed at a position where the minimum dose is likely to occur. In situations where the position of the minimum dose is not accessible extrapolation from the dose observed at a reference position is less reliable. (author)