Cumulus Support

I'm new to this site, Cumulus and weather stations. I'm from Australia and located at 35° 5' 7" S 139° 53' 34" E in South Australia.

I recently purchased a WH-1081 and decided to match it with Cumulus rather than EasyWeather after reading all the good reports about Cumulus. Everything about the WH-1081 worked fine out of the box, excepting the rain sensor. It gave all sorts of readings when there was no rain, which I put down to wind tipping the buckets. I then used some tape and prevented the bucket from tipping, but I still got rain readings, even when there was no rain.

This had me baffled. I made an assumption that the magnets in the wind sensor were somehow causing the rain sesnor to randomly activate, despite having installed the station as per the instructions and the illustrations.

I've now made my own tower which takes advantage of the length of the cable on the wind and rain sensors. The wind sensor is at the top, some 5+ metres off the ground, with the transmitter (which includes some other sensors) approximately halfway down. I placed the rain sensor at the bottom, positioned about 1 metre off the ground and shielded from wind entering from underneath by placing it on a metal box that stops wind from tipping the bucket. I've also placed a rainguage alongside the WH-1081 rain sensor at exactly the same height.

Since making these mods, I have not had false readings from the rain sensor (3 days). Last night we had some rain and the system registered 2.4mm over several hours. I was awake at the time watching IPL so I was able to observe the readings being recorded.

When I checked this morning, the rain in the guage alongside was approximately 2.7 - 2.8mm. When I checked the sensor buckets, one had some rain in it and would have taken only a little more to tip it and to register 2.7mm overall. Not a bad result I thought.

In my opinion, the lack of depth to the collection funnel of the WH-1081 is the real weakness with the device as rain drops would splash out in heavly rain or may even blow out in stronger winds. I shall work at finding a suitable material to extend the height of the sides of the collection device to see what effect it has.

I've read with interest the different posts relating to the WH-1081 and similar Fine Offset weather stations, particularly the rain sensor issues. From what I have read, no other members have mentioned the false readings I have found occur when using the standard installation. I'm interested in what others have to say about this and my other thoughts.

Bob

Bob, I'm convinced from data that I've seen, that as well as being susceptible to the buckets being tipped by the wind or vibration, these station also generate false rain due to some sort of interference - rather like Gina is seeing with her temperature spikes.

Interference can cause a deluge of virtual rain - as I have found in the past when I had the rain gauge too close to an electric fence!

G'day Bob, great to see another South Aussie on here!! Have you set up a website for your weather station? If so get it added to the Cumulus Map.

I have made the mod pictured below to the rain collector to get around the movement problem and also the problem with shallow sides. It collects exactly 3 times the rain as the old rain gauge and Cumulus calabrates it. It's just a pot with a funnel glued in place sitting over the top of the old collector and can be removed without any changes to the original. I have 2 other rain guages in the garden and this has proved to be very accurate and I have not received any false readings to date.

Thanks for the feedback. That looks a very interesting mod "hills".

I'm looking at adding a funnel mod to achieve better accuracy. I've done a few calculations and I figure a funnel of 83.6mm diameter would maintain the surface area of the existing collector which is 55mm­­­ x 11mm. I'm currently looking for a suitable funnel.

In answer to your question about a website for my Cumulas data, I need to get a site organised. It shouldn't be a problem but I just have to get around to it.

Bob

Epic thread dredge, but just wanted to make a note of something.

We have had a lot of rain and high winds lately, and it seems I have experienced our first inaccuracy due to wind affecting the rain readings.

Looking outside and seeing our neighbours tv aerials, I noticed they were shaking due to the wind.

So, it may not necessarily be the wind tipping the buckets, it may be the mast you have the rain guage mounted on also rocking in the wind, with the motion causing the (possibly empty) bucket to tip.

May also be possible on the standard pole included in the kits too.

Can't be bothered correcting all the readings (will adjust the records though).

Will mod by mounting the rain guage (finally) on the roof rather than the aerial mast.

Thought I'd let you guys know what I thought anyway.

Yes, the rain gauge needs mounting firmly so it doesn't rock in strong winds.

Keyz wrote:Epic thread dredge, but just wanted to make a note of something.

Looking outside and seeing our neighbours tv aerials, I noticed they were shaking due to the wind.

So, it may not necessarily be the wind tipping the buckets, it may be the mast you have the rain guage mounted on also rocking in the wind, with the motion causing the (possibly empty) bucket to tip.

Yes, have to agree. I now have my rainguage mounted firmly (and not on the pole) as I am sure it was causing all sorts of false readings when mounted on the pole.

Bob

I have mine mounted on a fence post, by its self two feet above the ground, using the mount that came with the station. A few days ago, I was standing next to the rain gauge in a 10 mph wind. Just as y'all said, the gauge was twisting and swaying back and forth. It did not show any false bucket tips but I would think a big gust would sure make it happen. This would be especially true if the frontal area of gauge is increased by a add on.

I am going to put mine on a 4"X4" wood post without the pole mount they supplied.

This is my support system. Recycled garden chair frame (painted with Hammerite to stop further rusting) and hammered into the lawn. This is my latest creation of rain gauge mod. I'll post more pics later.