A new monitoring technique of surface contamination - the test surface method

A new technique for surface contamination monitoring, aimed at overcoming some of the disadvantages of the smear method, is described. A piece of test surface material is stuck on to the surface to be monitored. At the end of the working period it is stripped off and the radioactivity accumulated on its outer surface is measured. Of various materials considered, an unwoven fabric on an adhesive tape was found to be the most satisfactory. The procedure is very simple, measurements are not affected by the surface to be monitored and the test material can be applied to complicated surfaces, e.g. door handles. A piece applied to the sole of a worker's shoe can be used to monitor large areas. On the other hand, loose and fixed contamination cannot be measured separately. Results of using the smear technique and the test surface method together suggest the practicality of the latter as a routine monitoring procedure. (author)