I have been testing a home-made heater for my Vantage Pro 2 AWS rain collector
during this snow event.
So far results have shown it to have been quite useful.

It consists of two 12 volt car tail lamp light bulbs, which I happened to have
to hand in the garage (amongst a million other odds and ends!) The ones with
two elements - 21/5watts.

I wired up the two 5 watt elements in parallel, with a bulb held vertically on
either side of the tipping bucket, close to the side of the collector. The
power is supplied by an old Virgin Media modem power pack, with an output of 12
volt/1 amp.

These are the results of the water measured compared to that measured both in
the 5" standard copper gauge and 5" funnel 'plugs' melted in accordance with
Met O Observer's Handbook.

19/0900 AWS 7.6 mm 5" gauge 7.3 mm (took 12 hours to melt it all in AWS!)
21/0900 AWS 3.2 mm 5" gauge 3.6 mm (melted in AWS as it fell)

I realise that evaporation may be an issue, but I believe it to be small in
comparison to the convenience and usefulness of having both the AWS and the 5"
values to hand.

Obviously a higher wattage would be required at colder air temperatures.

Roy Avis
Bracknell Weather at:
http://www.weatherfamily.org/bracknell
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