Re: 5. Wire less Alarm Systems certification extend..

[-pull@shoot]

On Thu, 05 May 2005 09:33:03 +0200, -pull@shoot wrote:

>Some pro's say that wireless alarm system are certified and due to
>that Radio Frequency Interference (RFI) protected, lets put it in the
>right context.
>
>Let's show that the equipment certification process has nothing to do
>with RFI protection and detection.
>
>What is covered during equipment certification?
>
>1. Equipment Radiation
>   All "internal generated unwanted" Radio Frequency (RF) signal
>   produced by most equipment's is tested during certification and
>have
>   to be under an external measurable signal level defined by the
>   ElectroMagnetic Compatibility (EMC) tests with typical certified
>(CISPR requirement) measuring devices.
>
>2. Equipment Immunity
>   Equipment's have to satisfy a second part of EMC certification,
>they have to undergo tests to show they're immunity against
>   Radio Frequency transmissions generated by equipment as here above
>   in item 1.
>
>3. RF Receiver immunity test (?)
>   There is NO external Radio Frequency Interference (RFI) signal
>   immunity or detection test for "receivers".
>   The receivers have been designed to capture specific signals
>   emanating from the sensors (transmitters) and are designed to
>   reject unidentified sensor signals but can't avoid unwanted signals
>   to reach them and jeopardize they're operation when they are
>   generated in a continuous manner on the receiver frequency (no
>   identification).
>
>This being said:
>- there is no certification test for RFI "immunity" caused by
>  RF transmitters as mentioned in part 4;
>- there is no certification test for RFI "detection".
>
>Professionals say that some newer systems detect interferences on
>Wireless alarm system by stating features not designed for that
>specific purpose!!!
>
>Professionals claim they had no interference detected during the last
>20 years!!!
> That's for me at least a good prove that RFI is not detected, the
>system goes "bingo" and nobody knows.
>
>Paul