[Examination of optimal radiation quality in the lead equivalent examination of X-ray protective clothing].

To determine the effective lead thickness of the apron for radiation protective clothing, i.e., the lead equivalent, a method of performing the lead equivalent examination is provided in the Japanese Industrial Standards (JIS). We proposed a method of computation using an attenuation coefficient, and examined the measurement accuracy and optimal radiation quality using both methods. We were able to compute the lead equivalent with sufficient accuracy when using radiation quality of about 60 keV in the range of radiation quality examined. This technique was also examined in the measurement used for the marketing of radiation protective clothing.