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Fine Offset w8681 (1080/1) Rainfall detector

For discussion of DIY weather equipment - sensors, accessories, improvements to existing kit etc
Gina
Posts: 1885
Joined: Sat 21 Feb 2009 12:41 pm
Weather Station: Nothing working ATM - making one
Operating System: OS X, Linux Mint, Win7 & XP
Location: Devon UK

Re: Fine Offset w8681 (1080/1) Rainfall detector

Post by Gina »

I was thinking of increasing the size so that it would register light showers, which it misses at the moment. Only problem might be overload in a deluge. Does anyone know the maximum rainfall rate the present unit will take?
Gina

Sorry, no banner - weather station out of action. Hoping to be up and running with a new home-made one soon.
Gina
Posts: 1885
Joined: Sat 21 Feb 2009 12:41 pm
Weather Station: Nothing working ATM - making one
Operating System: OS X, Linux Mint, Win7 & XP
Location: Devon UK

Re: Fine Offset w8681 (1080/1) Rainfall detector

Post by Gina »

I think I've got the answer to that myself. Yesterday when I was trying new positions for the temperature and rain gauge I got interference from an electric fence - a pulse about once per second and that gave a rainfall reading (1000mm/hr) something like a hundred times the UK record! I figure the buckets and electronics are well able to cope with anything we might get in this country with a 3x increase in catchment area.
Gina

Sorry, no banner - weather station out of action. Hoping to be up and running with a new home-made one soon.
hills
Posts: 690
Joined: Sat 26 Dec 2009 8:52 am
Weather Station: Fine Offset WH1091
Operating System: Raspbian Buster
Location: Crafers, South Australia
Contact:

Re: Fine Offset w8681 (1080/1) Rainfall detector

Post by hills »

here's what I built. Its just a funnel cut back to a 13.8cm diameter glued into a container I had lying around. It just sits over the existing gauge. I also have a manual rain gauge so if we ever get any rain I'll see how close it is. My calibration is .33

Image
andyjrb
Posts: 15
Joined: Tue 01 Dec 2009 4:44 pm
Weather Station: WH1090
Operating System: Vista

Re: Fine Offset w8681 (1080/1) Rainfall detector

Post by andyjrb »

I discovered the other day that my rogue 0.3mm readings, which occurred on very still days, were due to birds landing on it (the gauge is near the bird feeder)
Gina
Posts: 1885
Joined: Sat 21 Feb 2009 12:41 pm
Weather Station: Nothing working ATM - making one
Operating System: OS X, Linux Mint, Win7 & XP
Location: Devon UK

Re: Fine Offset w8681 (1080/1) Rainfall detector

Post by Gina »

I've nearly finished my modified rain gauge. I'll take a photo of it tomorrow. Only other thing I want to do to it is add a thermostat controlled heater to melt snow and stop icing up. Circuit designed, now I need a couple of components and to make it up. Snowing heavily here and has been since late afternoon.
Gina

Sorry, no banner - weather station out of action. Hoping to be up and running with a new home-made one soon.
zaax
Posts: 20
Joined: Tue 02 Jun 2009 11:12 pm
Weather Station: WH1081

Re: Fine Offset w8681 (1080/1) Rainfall detector

Post by zaax »

Look like the rain sensor is a built in problem with the magnet and reed switch (and spiders which were doing loop-the-loop last night when I was changing the battries).

http://www.digitalham.co.uk/equipment/Watson_W8681.php
SUBYDAZZ
Posts: 207
Joined: Fri 01 Jan 2010 1:04 pm
Weather Station: Oregon Scientific WMR200
Operating System: Windows 11
Location: Singleton, NSW, Australia
Contact:

Re: Fine Offset w8681 (1080/1) Rainfall detector

Post by SUBYDAZZ »

I'd just like to point out rainfall isn't uniform even over a very small area. It can vary quite a bit (try putting out a few gauges of the same type in a particular area). In the PWS photo shown here, wouldn't the rain catcher be shaded somewhat by the close proximity of the rest of the station to it anyway, giving yo less accuracy with wind blowing from certain directions?
Gina
Posts: 1885
Joined: Sat 21 Feb 2009 12:41 pm
Weather Station: Nothing working ATM - making one
Operating System: OS X, Linux Mint, Win7 & XP
Location: Devon UK

Re: Fine Offset w8681 (1080/1) Rainfall detector

Post by Gina »

I've placed mine well away from the other sensors and from trees and bushes etc.
Gina

Sorry, no banner - weather station out of action. Hoping to be up and running with a new home-made one soon.
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