On Fri, 28 Mar 2008 19:58:59 -0000, "Mike Lewis"
wrote:

I've discovered that the problems we've been experiencing on our Instromet
weather station with regards to spikes in rainfall and windspeed data is due
to RF interference. The source of this is going to be difficult to track
down, but one solution I've read is to fit a ferrite? to the serial cable
connected to the PC.
You have not described the unit wiring/cabling setup. Is it a single remote unit
with a single RS232 cable back to the PC? Or is there more wiring involved? How
is/are the remote unit(s) powered?. Is the signal cable screened? Length of
cable? Ground level or elevated?
Basically does it /look/ like an aerial?
RF signal are usually present for enough time to pass a message of some sort
(speech/data) and a local transmitter could result in your aerial picking up
enough to upset the sensors (probably not the PC). If you have virtually
continuous recording data and only get narrow spikes then I would be more
inclined to suspect the power source.

Geo