Safe Speed Forums

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I'll mention the serious window problem, but does anyone know about the mobile phone mast?

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

One would hope that part of the Home Office Type Approval was a requirement to conform to current regulations regarding production and tolerance to EM interference. Mind you, would have also hoped that it included tests on bikes!

The manuals make very little reference to RF interference. This is all they say about it:

"The L TI 20.20 TS/M Speedscope is not susceptible to radio frequencies and electromagnetic interference, therefore, checks are not required (as with radar) to identify such potential problems."

Which is of course nonsense because all electronic devices have a threshold of susceptibility. The ACPO code of practice (which Frank Garrett contributed towards) makes reference to handheld radio devices in Appendix A, so suggesting they are indeed suspect able at some level. No reference is made to masts.
(I have it on good authority that nearby mobile media relay vans indeed roger the LTIs)

I reckon such a metal cased device should easily pass the light industrial or product family standard test levels, which is all a UK used, non-military device needs. To determine compatibility, the distance from the mast where the field strength is 10v/m needs to be calculated; such equipment used within that distance is technically at risk of being interfered with.


Regardless, given the error detection algorithms employed within the LTI, I strongly believe there is a phenomenally low probability of getting a false reading when interfered with in such a manner; errors yes, but not a false speed reading. Undetected error due to slip is much more likely.

It is electronic equipment, and so there is scope for EM radiation to induce current in its circuitry. Therefore, it is required to comply with the EMC CE marking directive before it can be legally used within the EU.

So, is it CE marked? If so, is there a declaration of conformity WRT EMC? If the answer to either of these questions is "No", I suspect that Garrett's company at least are guilty of one or more offences under CE marking legislation.

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Will

I Have been involved in much EMC testing. Most items can be failed at some level or another. There are various levels for immunity Industrial,domestic,special and so on. You are allowed to fail and put in your declaration of conformity " Do not operate in areas of high EMC " you can even fail as long as the item recovers operation afterwards. it is not a pass not pass senario. Also ALL software will have bugs what version of software is current ? It could easily be 10 or 20. I would say the software should meet some basic safety criteria such as Ticket or software for safety critical systems - you can bet your bottom dollar no such system or quality system 9001/9002 has been properly used/applied.

Richard