Re: Use of Portable Radiation Monitoring Equipment

[Ccja@aol.com]

I would think that a pocket chirper, or a similar personal alarming device,
would be sufficient, if another level of backup is thought necessary, in the
case of a teletherapeutic machine. You could buy several of them for the
price of a single survey meter. Note that, with most such machines, it would
be relatively difficult, in most cases, unknowingly to enter the path of the
direct beam, with a large portion of the body, even if the shutter were to
stick open, because the positioning of the gantry tells you where the beam
would be. So, the possible saturation of the device should not be an issue.
An exception might be, e.g., a total body irradiator, especially one that
used two sources in an opposed configuration. Even there, though, the device
could be adjusted to alarm at whatever worst cases of exposure conditions
could be encountered in the maze.

I recommend the use of a survey meter, in the case of HDR sources, because
you kill two birds with one stone. I.e., reassuring personnel that they are
not being exposed, and fulfilling the regulatory requirement to survey the
patient.

chris alston
ccja@aol.com