On 9 Apr 2017 13:40:53 GMT, (Volker Borchert)
wrote:

Neon John wrote:
On 8 Apr 2017 05:50:33 GMT, (Volker Borchert)
wrote:

John B. wrote:

Loctite 7414 tamper detection paste ?
http://tinyurl.com/m7le3vd

What if the tamperer buys that stuff too?

I've been in the situation a couple of times in my life where
tampering and cover-up was likely. I used fingernail polish to which
I added a tiny amount of a specific mixture of radioactive elements.
Detecting a forgery is as simple as holding a sensitive Geiger counter
to the dot.

Nowadays one might use DNA "ink".

A DNA analyzer is a tad bit more expensive than a Geiger counter with
a pancake probe and you're certainly not going to carry the analyzer
out into the field.

I mix my isotopes in a specific ratio so if an argument ever arose
about the authenticity of the radioactive dot, I simply analyze the
dot with my gamma spectrometer to look at the ratios and the relative
decays.

Another option that is becoming more and more practical is to mix a
specific ratio of elements, preferably metals, in the dot. Then use
one of the hand-held laser ablation atomic absorption spectrometers
that scrap metal dealers use to determine the composition of an
unknown alloy before bidding on it. Only problem is they cost about
$25k currently.

I have a friend who had a large scrap metal operation. He has a gun.
I can sometimes talk him into letting me shoot an unknown. He tends
to hover when I'm using it.

Like most discussions on Usenet, this one is getting rather esoteric.

If I had a serious tamper problem, I'd have a chemist friend supply me
with some photochromic paint he developed. It starts out bright
orange but rapidly turns brown. The authenticity proof is to break
the seal, preferably with a video camera looking on. The interior
will still be bright orange and will darken before your eyes. If the
tamperer has tried to hide his tampering with brown putty or paint,
it'll be brown even when first broken.
John
John DeArmond
http://www.neon-john.com
http://www.tnduction.com
Tellico Plains, Occupied TN
See website for email address