Davis Rain Gauge "FYI"

[Dr_G]

Hello again,

Got the VP2 up and running, and all seems well. I did however have slight problem with the rain gauge. It was working fine for a few days, then intermittently, then not at all. After much faffing about checking continuity, plugs, sockets and reed switches, I found it was the reed switch that was going. Difficult to trace because it was switching when checked with a meter, but with a very high resistance - not enough to register a pulse when raining. I only found this for sure by substituting with a new one. Once replaced it is again working perfectly.

If anyone needs a new reed switch - forget the importers of Davis Instruments or any of their retaillers - even when they tell you they have them is stock they won't sell them to you unless you send the ISS back for repair. Anyway, assuming the reed switch was the original (presumably so Mr One-nil?) then the good news is that they can be obtained from Bardwells Electrical shop in Sheffield (one of the seven wonders of Sheffield no less!). The cost is an almighty 20p . I must admit that I didn't remove the old reed switch before buying a new one. I assumed that it was encased in plastic (hence the 'do not touch reed switch' sticker next to it) and would be impossible to find a direct replacement. However, when I finally tried to remove the switch, it turned out that it was covered by a bit of black plastic snapped on to the base. Under this is the glass reed switch which was totally identical to the one I'd just bought, even down to the green tint of the glass and gold contacts (see attached image). As far as I can see, despite the dire warnings of the aforementioned label, touching the reed switch itself is impossible, but if you knock the wires coming out of it (like I probably did at some stage) then it is very easy to crack the glass slightly and then the switch contacts will corrode and eventually fail.

I also made a leaf guard out of a B&Q drainpipe filter (see attached image). I cut the plastic base off it, and glued some brass wire to the ends of the 'spider' to stabilise it in the gauge. Seems to work well enough in terms of not obstructing rain, we will see how well it filters leaves!

Hope this is of help to someone somewhere!

Cheers,

Garth.