Sandaysoft

Yes, I've often noticed the inside of the funnel covered with droplets of water. There have been suggestions for sprays to help with this but I don't know how well they work.

As for overloading the buckets, I thought of this before when I used the first extra funnel and did a test. This showed that the buckets were happy with many times the maximum rainfall rate recorded in the UK. But then I was considering a 4x increase in catchment area - 8x or 12x may be a different matter. I may conduct the test again with my spare rain gauge.

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Gina

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

Been doing some thinking... Currently I get a bucket tip for 0.1mm of rain. 50mm/hr is really exceptional rainfall rate and rarely occurs in this country. On the occasions when it has, there has been severe flooding. To make the arithmetic simpler, let's take 60mm/hr - that is 1mm/min. ie. 10 tips/min or 1 tip every 6 secs. If I increase the sensitivity by a further 3x (with a whopping one foot diameter funnel) that would be one tip every 2 seconds. I'd have thought the buckets could cope well enough with that.

Now tell me my maths is totally "up the creek"

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Gina

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

The problem is that you can get very brief periods of much more than 50 mm/hr; a couple of days ago we had a downpour and hit 80 mm/hr briefly. TBRs under-read in heavy rain, partly because of the rain that they miss while tipping; if it were tipping once every two seconds or even faster for any length of time, you could expect to miss a significant proportion.

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Steve
Sanday Weather
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Had a similar problem recently which turned out to be due to the "sticky" substance eft by Affids? which basically stuck the bucket in one position!

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Thanks for your reply Steve. Yes, I can see that they miss some rain whilst tipping. Maybe that's why the better makes are 7 or 8 inches diameter - best compromise.

I might make up a second rain recorder later on and connect it separately to computer. I have a Velleman K8055 USB Experiment Interface Card (bought from Maplins) which has 5 digital and 2 analogue inputs, that I use for such experiments. I'd also be interested in getting a better indication of rain rate than I can at present. When/if I get something working, I'll post about it in the Homebuilt forum, as it doesn't belong here.

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Gina

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

Anybody have any more ideas about increasing the accuracy of the rain guage. Rather than increasing the funnel size I thought of just raising the side walls higher by attaching some other rigid plastic sheets. That way water won't splash out in heavy downpours but I don't mess with the calibration of the system?

I have also noticed water beading on the surface. Someone mentioned a spray what have others used/tried. Also I was just thinking with my raised wall idea, could I just make my own funnel (i'm thinking with an ice cream container cut up) with the same aperture size but steeper ramps inside so the water must slide down?

I extended my sides straight up about 3". So far it is dead solid perfect.

Randy

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Georgia Home Orchard

http://georgiahomeorchard.blogspot.com/

What did you use?

I am with Steve on this, especially today, it seems like it has started bucketing down outside here, yet it took a while for it to register the first 0.3mm. I guess you have to think deep down really how much exactly is in one single raindrop, and how many raindrops enter the raingauge.

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Rob,
Dyffryn History on WU Dyffryn on Twitter Dyffryn on WOW

OK I have made this!!!! Just needs a bit more duct tape...I ran out! The funnel is the same size as the gauge top but 3 inches high then I added a further 1.5 inch wall to the top. I just used some rigid plastic and the aforementioned duct tape. So I am hoping this almost zeroes errors due to splashing and low rain rate beading.

That looks great I wanted more response to light showers so used a large funnel.

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Gina

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

Yep I read your posts Gina but I wanted the station to still show the correct info. I was however impressed when I read/realised that the funnel has the effect of increasing the fidelity below 0.3mm. Bonus!

I just changed the multiplier in the software (both Cumulus and G-Weather).

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Gina

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

My rain gauge and, in fact, the whole weather station is still working fine. Except for picking up spikes from our electric fence when it's on. I have some ideas about that like a new mast with the cable inside it. I expect to do that in the spring.

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Gina

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