RADIATION DOSAGE INDICATOR

摘要

A multi-ply radiation dosage indicator (10), and method of manufacture, is disclosed including a first ply (12) having visible indicia (14) thereon and a second ply (16) having a radiation sensitive zone (18) overlying the indicia (14) of the first ply (12). The radiation sensitive zone (18) is capable of changing opacity in response to exposure to a radiation dosage exceeding a predetermined threshold so as to change the visibility of the indicia (14) thereby providing an indication as to whether the indicator (10) has become irradiated. An optical filter ply (26) may be provided overlying the indicia (14), and the indicator (10) also may be provided with a transparent protective outer ply (19). A pressure sensitive adhesive ply (30) having a removable release sheet (32) is employed for attaching the indicator (10) to a substrate.