Paul Corfield wrote:
On Sun, 14 Jun 2009 16:29:37 +0100, "Graham Harrison"
wrote:

Waiting for a North London train a couple of days ago the
station
person (what are they called these days?) came down onto the
platform carrying what looked like a mobile phone. He went
behind
the side of the shelter and appeared to hold the "mobile
phone" to
the fence (the fence was creosoted a very dark colour). He
appeared to do the same thing in more than one place on both
platforms. When I looked there was a black "stud" (only
word I
can think of) which was simply inserted into the fence
panel - it
wasn't a fastener, there was not a post or anything behind
the
panel.

Is there any significance to his actions?

The "studs" are almost certainly a location identifier that the
hand
held unit will read. By holding the unit against the stud it
shows he
has been to the area as part of a planned inspection. Bar codes
can
also be used. I have seen building security staff use this
system to
prove they've undertaken their rounds. LUL is trialling
something
similar to be able to record the fact that hourly security
checks
around the station have been completed.

We had a system like this at work - referred to as a "Deister". I
presume they are the manufacturers.

--
MatSav