spyproofing your house/work building

Chris Knight cknight at crl.com
Tue Mar 15 13:02:16 PST 1994




On Tue, 15 Mar 1994, Perry E. Metzger wrote:

> > Make sure the drapes block IR.  There are instances of even local
> > police forces flooding the front of a house with IR light,
> 
> You mean heat? What did they do, exactly? Erect giant heat lamps in
> front of the house? No one inside noticed either?

IR does not mean heat.  Infra-Red only implies having a wave frequency 
lower than that of "red" light.  There are several bandwidths of IR used 
for nightscopes that cannot be felt as heat, nor do they increase 
the surface temperature of the target area to a noticable extent.

-ck







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