Glass distinction
(In his feature on glass break detectors, Tony Earl of Elmdene International gave a structural insight into glass itself…)
“Glass belongs to a class of ceramic material categorised as a non-crystalline solid. All members of this family share a molecular structure containing a number of different molecular arrangements, which exist in proportion to the ease with which they are formed. Easily formed arrangements appear the most frequently and give rise to the presence of a number of different resonant frequencies within the glass structure, each corresponding to a particular arrangement of molecules.
“They are characteristic of all glass, regardless of physical size and shape. For example, a small pane of glass six inches square will exhibit the same resonant peaks as a laminated shop window front 10 feet square. This is due to the internal molecular structure of the glass, as described earlier, and not the macroscopic dimensions of the piece under scrutiny.”
First private monitoring
(A Newsdesk item reported on the first private monitoring of an industrial estate…)
“The Metroplex Centre in Greater Manchester is the first private industrial area to be monitored from an independent surveillance station. The result of a three-way investment shared by Advanced Technologies Industries, the developers and the 35 tenants, the hi-tech system has been set up augmenting existing individual arrangements.”
Howlers
(As a light-hearted conclusion to his article on the City & Guilds 185 Masterclass syllabus, the author, Michael Taplin, recounted some howlers from past papers…)
“The marking of examination scripts is, understandably, time consuming and very demanding: an examiner with 250 scripts faces some 40 to 50 hours of concentrated marking.
“The required degree of assiduity on the part of the examiner is alleviated by the amusing responses of some candidates to various questions. Here is a short selection of genuine howlers from this summer’s paper: “On describing the function of the sensor in a passive infrared movement detector: The sensor is a pyro-technic device…it picks up any radioactive heat in the area.
“And the function of the monostable in the same detector: The monostable cheques the frequency of the ampage.
“On stating the precautions to be taken when installing a movement detector: Have it mounted on a stable base…also make sure the YTS boy wires it correctly.
“Sorry – no names. It wouldn’t be fair!”
What a site!
(Paul Spooner of Larkins Security Systems passed on his tricks of the trade when installing CCTV, and included this advice on choosing a site for equipment…)
“When positioning equipment, cameras, etc, consider the problems of the poor maintenance engineer. Cameras sited high on the side of buildings or an overhang seems ideal, but when you have hired extra long ladders or cherry pickers for the umpteenth time just for a simple problem, the inconvenience will soon be realised.
“Cameras should be firmly fixed using all the fixing holes provided on the bracket to give a safe and sturdy fixing. If fixing to metal-clad buildings (they are becoming more common), make sure to fix to a supporting member or use plates to spread the load and stop camera shake.”
