Cumulus Support

There was some frost recently (see chart) and this morning it started to rain at -0.3 degrees. But the WH40 did not register anything so I assume it is frozen. This makes it les useful in the lowlands with mild winters with around freezing point weather. The inner parts should stay dry, at least not be blocked by freezing condense or otherwise entered water. That is something which never happened with my Davis.

What can happen (not only with a WH40 but also with the rain gauge of the WH65/WS69 array) is, that the water in an almost completely filled spoon freezes, becomes heavier and tilts. As the ice is stuck to the bottom of the spoon, the spoon remains in the tilted position and won't count anything (until the ice is melted). Had had this phenomenon with a WH65/WS69 installation recently.

My way to circumvent/avoid this is having built a temperature dependent heating inside the WH65/WS69 rain gauge. The heating is performed by a terrarium reptile heating coil (15 W) and I have set the thermostat to 0.0°C to engage and +3.0° to release. Works perfectly. Already now for three winters with temperature below zero °C.
I just have wound the heating coil loosely inside along the wall of the rain gauge making sure that the tilting mechanism of the spoon is not affected. Example: https://www.amazon.de/32008-reptil-cabl ... 198&sr=8-5

As the WH40 has even more space, the same approach should work there too. Maybe more wattage needed due to the bigger size, but there are also coils with higher wattage.
The system works on a 240 V power supply though. Depending on the location that might be a challenge and a low-voltage solution might need to be applied.
In fact it is a simplified setup of what is described here (in German) for a Davis rain gauge:
https://www.nimmervoll.org/wetter/stati ... izung.html
Even without knowing German, the pictures tell most of the story.

Gyvate wrote: ↑Sat 25 Dec 2021 9:21 pm What can happen (not only with a WH40 but also with the rain gauge of the WH65/WS69 array) is, that the water in an almost completely filled spoon freezes, becomes heavier and tilts.

What you propose sounds like a great solution. I have a problem with your quoted statement above, though, as liquid water is heavier than ice.

freddie wrote: ↑Sun 26 Dec 2021 2:43 am

Gyvate wrote: ↑Sat 25 Dec 2021 9:21 pm What can happen (not only with a WH40 but also with the rain gauge of the WH65/WS69 array) is, that the water in an almost completely filled spoon freezes, becomes heavier and tilts.

What you propose sounds like a great solution. I have a problem with your quoted statement above, though, as liquid water is heavier than ice.

Correct, it was a simplification in the description. What probably happened was that some water would still drop on the ice and also freeze. Like this the ice built up and finally became heavier and made the spoon tilt.
I've seen the lump of ice on the tilted spoon which arched higher than the rim - unfortunately I forgot to take a photo before I removed it.
It was on my Godchild's installation who lives quite far away from me.

In any case, the inbuilt heated reptile cable/coil prevents that from happening in my installation.

@Gyvate: Thanks for the advise, but bringing 220V to the station (the WS80 is even more awkward placed) is not possible since there is a small ditch usually carrying water. And besides the pasture is not mine. But I am working on a solar powered stevensons screen, so that may become a solution. However, winter is never the best of times for solar power
Anyway... on my todo list, thanks.