Retail scan point

["Randy Ross" <RNROSS@BCSC02.GOV.BC.CA>]

Radiation Protection Section
BC Ministry of Health rnross@bcsc02.gov.bc.ca
The point is,a scanned laser beam seems bright..."seems" bright to the
eye.  That means it is bright to the eye.  It's also a laser (fear enters in he
re).  Try staring into the retail scanner beam.  Yes that's right hold up the l
ine and don't tell anyone where you work just let them think what they will and
 you will see if you can manage to get a beam to cross your pupil a few times
I've done it and it does seems bright!
I did a study on some class 2 (.9mW/cm2) HeNe alignment lasers used on patient
s.  This beam was not scanned but spread into a long thin line.  The line ran
down between the patients eyes and as a result frequently the patients got a
portion of the beam line in the eye.  After making the calculations and measure
ments I concluded that the patients had nothing to worry about as far as eye
damage goes.  there was a safety factor of 200 ie the irradiance levels at the
cornea were 200 times below the threshold for injury.   So I decided to see wha
t it was the patients were complaining about.  Well let me tell you it was
VERY bright.  It was like looking into the sun.  But it was not hazardous.
So the point is the retail scanners may not be hazardous and as many have
pointed out they are scanned so there is much less energy than an alignment
beam  they still SEEM bright.  That together with the fact that they are "laser
s" is a problem for some people with common sense.

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Material and opinions above are those of the author and not
those of BC Systems or the BC Ministry of Health