摘要 |
<p>An instrument for checking appts. for measuring gamma radiation comprises a thick-walled lead housing in which is placed a radioactive source emitting gamma radiation, of given constant characteristics, through a measuring window closed by a calibrated plug. Lead doors, articulated on the housing, can be closed over the window to attenuate the radiation by specific amounts. The instrument placed at the entry of a radioactive zone, allows the user to check the functioning of a radiation meter over its whole range of measurement, before entering the zone.</p> |