Trixology
Weather => Weather Hardware/Measurement => Topic started by: elagache on February 19, 2014, 10:13:54 PM
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Dear WeatherCat Davis Vantage Pro-2 owners,
We weren't supposed to get any rain last night, but a storm went a little further south than forecasted. When I woke up, the ground seemed wet enough to have tipped the rain gauge bucket, but there was nothing showing up on WeatherCat. Then at about 8:30am - surprise! By then the storm was long gone and there was bright sunshine.
This isn't the first time this has happened. Sometimes it can be as much as 12 hours after the actual precipitation event before I get the final bucket tip of the storm. I had assumed that the bucket had come very close to tipping and something "knocked it over" like a bird landing on the gauge or perhaps a small earthquake.
I suppose it could still be always a fluke, but I'm curious, anybody else seeing this sort of "retarded" bucket tipping behavior? Could thermal expansion be partly to blame? Any other thoughts?
Cheers, Edouard [cheers1]
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Edouard:
I get delayed bucket tips from time to time, but never anything more than 30 minutes.
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Its doesn't happen all the time, or maybe I don't always notice... But I've had delayed tips. Doesn't happen all the time. About the time I decide to check if a bird or tree has plugged up the collector...I get a tip.
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I've had situations where I thought it should have tipped in a brief shower, but it didn't. Haven't noticed any delayed tipping.
I might offer an explanation, though. If the tipping spoons are getting a little grimy, perhaps with a thin film or an accumulation of a small amount of electrostatic particles or a thin trail of mud cake along the bottom of the spoon from the dust in the air that collects in the first rain, it can hold moisture on the inactive spoon. That moisture as a counter weight can keep a spoon from tipping at the right moment, but without more rain, dry and restore balance.
It's just a possibility.
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Wind? I've had mine tip on really windy days when we've had no rain.
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Dear Blick, NoWait, Herb, Steve, and WeatherCat Davis troubleshooters,
Thanks for the observations and suggestions!
I might offer an explanation, though. If the tipping spoons are getting a little grimy, perhaps with a thin film or an accumulation of a small amount of electrostatic particles or a thin trail of mud cake along the bottom of the spoon from the dust in the air that collects in the first rain, it can hold moisture on the inactive spoon. That moisture as a counter weight can keep a spoon from tipping at the right moment, but without more rain, dry and restore balance.
Well, there was some muck on the buckets so I went ahead and cleaned it all off with rubbing alcohol. I also went ahead and cleaned the collector cone and put on a fresh dose of Rain-X. That way the droplets will have a lower surface tension and will roll more easily into the buckets.
Wind? I've had mine tip on really windy days when we've had no rain.
I'm sure there is a final "nudge" that finally causes the bucket to tip and it could be a wind gust. However, the winds around here are generally much more mild than what you encounter Steve. That's a good thing, because with the sort of winds you see, my ISS would most likely get ripped off the side of the house!!
Thanks again gang!
Cheers, Edouard [cheers1]
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put on a fresh dose of Rain-X
Where exactly, and how often, does the Rain-X get applied?
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Hi Blick
I put it on mine late fall before the temperature get to freezing
hope this helps
cheers [cheers1]
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Randall, where do you apply it?
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hi Blicj11
Just clean the inside of the rain collector cone, then apply a light coating of Rain X to the inside surface should do the trick.
JC
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This is especially helpful for folks with extremely light rainfall or heaters in their collector. In both cases, the precipitation might evaporate before running down into the tipping bucket, so any help to get it measured is a good thing.
Steve