Electronics

Guest

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

Guest

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

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