Sandaysoft

It has possibly been well documented that the Fine Offset WH1081 and similar have a very shallow rain bucket. Around this time last year I modified the cover of my station to have larger sides using an ice cream plastic container. This worked well however the harsh New Zealand summer sun has taken its toll and is no longer useful.

However my work has started selling this type of weather station. After having a couple of returns I have made an almost perfect modification by using two rain covers.

Using a cutting tool, I took the centre out of one, flipped it upside down and used silicon glue with UV resist to attach it to complete one (unmodified). I also sanded down any rough edges to make a clean transition from one to the other.

Results look much more professional and will probably provide a longer lasting result to fix the shallow bucket problem.

I realise that not everyone has access to such resources, however maybe if you pop into a store selling this model, they too may have returns that you can use to achieve this. We usually give away any parts as replacement.

Undertaking this also helped pass a rather slow day at work.

This adaptation can also be seen on my live webcam http://palmyweather.co.nz/webcams.php

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Check my Palmerston North Weather Station out at http://palmyweather.co.nz .

I would have thought not, but any calibration needed on that?

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

I don't think any calibration would need to be conducted as it is the same catchment area surface, however it is just deeper, preventing any splash out. The only issue I may have is with snow, however it only ever snows here once every 80 years.

What do other people think, would it need any other calibration? Is this option potentially more or less accurate?

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Check my Palmerston North Weather Station out at http://palmyweather.co.nz .

This will fix the problem and make it more accurate. No calibration required. Although I would suggest setting up a manual unit to compare as even though the modification makes a difference, it still won't make it perfect. Whether you have made the modification or not, it's best to calibrate your unit and have good placement and fitting of your rain gauge.

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Michael, Palmerston, NT Australia www.Palmerston-WeatherNo image? I'm offline!

I did something similar with my gauge but I made a cut about 2/3 of the way up my old 1081 gauge (I upgraded to the 3081) cleaned the edges up and just sleeved it over my existing gauge as a shroud though mine is more aimed at preventing splashing out in wind as opposed to just conventional splash out itself.

I sanded the inside of the shroud with very fine wet and dry paper so it was all rather smooth too.

It doesn't look sealed. I would check by pouring in water and making sure it doesn't come out the sides. If it isn't sealed I suggest you do, as all water that enters through the top should be going through the tipper to be measured. Spare parts can definately be handy. I had to make my own with triple layered laminated sheets.

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Michael, Palmerston, NT Australia www.Palmerston-WeatherNo image? I'm offline!

its not sealed yet before I do so I'm cross checking the readings with the manual gauge as said its more a wind shroud as opposed to a sealed funnel design like your's also I'm in the process as I speak of building a DIY Stevenson screen for it based on the thread on here

I'd seal it first, as the harder the rain fall's the higher the error rate will be.
I'm in the design process of my own version of screen, it'll be a tube design, self ventilating to draw ambient temp air through during the day (no need for fans). Good luck with yours, post some pics!

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Michael, Palmerston, NT Australia www.Palmerston-WeatherNo image? I'm offline!

shall look at sealing it then very valid point

good luck with your design too, pics to come of this build, just about to bolt it all together and mount it

My problem is leaves. The shallow bucket gives the wind a chance to blow the leaves off the dish. How about a screen mesh that would allow the rain to fall through but would significantly reduce splash out?

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Fred
Hudson Ohio Conditions

I've finally got round to trying this modification myself, as I have a spare rain gauge. Before I set it up permanently, can I clarify something?

The top and bottom of the cover don't have the same catchment area. According to my calculations (which ignore the fact that the corners are rounded) the catchment area is approx 18% larger at the bottom than at the top. So if you flip it over as the OP appears to have done I think you would need to make an adjustment.

However he has achieved a much neater joint than if you keep the cover the right way up. I haven't fixed mine yet, but it looks as if it will need some mastic to make the joint waterproof, as the bottom of the top cover is larger than the top of the bottom coverand it won't fit neatly. (see photo)

Before I make my final decision, does anyone have further thoughts on this? And if I do fix it upside down with an area 18% bigger than the original, what adjustment should I make in Cumulus? I think it should be 0.85 as this is 18% less than 1.00, but maths has never been my strong point!

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Capel Dewi (Carmarthen) Weather Station:
http://wow.metoffice.gov.uk/latestobservationservlet?siteID=23385289
https://twitter.com/CapelDewiWeathr

Yes, that's right.

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Steve
Sanday Weather
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I would recommend you use some rain bucket shield like this http://www.met.tamu.edu/class/metr451/Ch9folder/451Ch9Precipitation/sld014.htm

This manual http://www.comptus.com/PDF/CWOP_Guide.pdf have some examples too. (page 45 onwards)

Good luck!

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Marco-Luis
YV1HX
Cabimas, Zulia, Venezuela
http://www.twitter.com/meteoven