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Weather Station Hardware => Hydreon RG-11 Optical Rain Gauge/Sensor => Topic started by: miraculon on October 31, 2014, 02:00:33 PM

Title: Snow on RG-11 vs. Heated VP2
Post by: miraculon on October 31, 2014, 02:00:33 PM
I just took a look at the Hydreon output today during the snow flurries that passed through earlier.
The heater in the Davis VP2 is working well (YARCH), but the behavior of the RG-11 is remarkably different during snow.
It appears that the Hydreon is catching snow flakes on a continuing basis, whereas the VP2 has to melt and tip.
Anyone else have experience with snow on the RG-11? This is the first snowfall since I have configured it as a tipping-bucket emulator. It was in "it's raining" mode previously at the old location.

I'll attach a plot for comparison.

Greg H.
Title: Re: Snow on RG-11 vs. Heated VP2
Post by: ValentineWeather on March 20, 2015, 01:29:04 PM
Greg how did your rain bucket heater turn out? I was looking for the original post but ran across this one instead. Most of my snows were under reported using the reptile heater mod vs the Cocorahs gauge. Did you have any better luck? I have a standard Davis heater I may try next year instead. Reason I didn't use it the switch went bad so I need to replace it first.
Title: Re: Snow on RG-11 vs. Heated VP2
Post by: miraculon on March 20, 2015, 02:15:26 PM
It works well at temperatures, say in the 20°F range, but as it gets colder it seems to slow down the melt rate. (not unexpected). I upgraded to the new Davis rain cone, and found that I needed to remove the debris screen. It was holding the snow and preventing melting.

Search the forum for "YARCH (http://www.wxforum.net/index.php?topic=22128.msg212803#msg212803)"*. The post for March 22, 2014 is the one showing the heater. I was not able to find the same bimetal thermostat that Davis uses. Mine is a 60°F open, whereas I think Davis' is hotter:

Quote
The heater assembly includes a thermostat switch. If the temperature at the thermostat reaches 110°F (43°C) the thermostat will interrupt power to the heater element.

I am not sure if this is really necessary in order to melt the snow. The 60°F seems to work fine. If you can find a higher temperature switch, it might help.

*"Yet Another Rain Collector Heater"  ;-)


Greg H.
Title: Re: Snow on RG-11 vs. Heated VP2
Post by: ValentineWeather on March 20, 2015, 02:27:53 PM
That was it YARCH. #-o I couldn't remember. I supplied the up close pics for your build. So a higher thermostat setting may be the way to go. Do you remember off hand what temperature the Davis unit was?  All I need to do is replace the on/off switch on my unit and it will be good to go for next winter.
Title: Re: Snow on RG-11 vs. Heated VP2
Post by: ValentineWeather on March 20, 2015, 02:41:09 PM
Found it: The heater assembly includes a thermostat switch. If the temperature at the
thermostat reaches 110°F (43°C) the thermostat will interrupt power to the
heater element. When the temperature at the thermostat drops to about 85°F (30°C) power
flow to the heater element will be resumed.
So yes they have a much higher temperature range.