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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 Feb 21, 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

Postby Gina » Thu Dec 31, 2009 12:31 am

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 Feb 21, 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

Postby Gina » Sun Jan 03, 2010 9:46 am

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.

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hills
Posts: 662
Joined: Sat Dec 26, 2009 8:52 am
Weather Station: Fine Offset WH1091
Operating System: Windows XP
Location: Crafers, South Australia
Contact:

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

Postby hills » Sun Jan 03, 2010 11:41 am

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 Dec 01, 2009 4:44 pm
Weather Station: WH1090
Operating System: Vista

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

Postby andyjrb » Tue Jan 12, 2010 6:55 pm

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 Feb 21, 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

Postby Gina » Tue Jan 12, 2010 10:28 pm

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: 10
Joined: Tue Jun 02, 2009 11:12 pm
Weather Station: WH1081

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

Postby zaax » Wed Dec 08, 2010 12:42 pm

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: 170
Joined: Fri Jan 01, 2010 1:04 pm
Weather Station: Digitech XC-0348
Operating System: Windows 7

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

Postby SUBYDAZZ » Wed Dec 08, 2010 3:41 pm

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 Feb 21, 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

Postby Gina » Wed Dec 08, 2010 3:43 pm

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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