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Weather Station Hardware => Hydreon RG-11 Optical Rain Gauge/Sensor => Topic started by: jerryg on February 09, 2012, 06:18:19 PM
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I got my sensor in today and got it powered up and tested in tipping bucket mode. I have it mounted on top of my stevenson screen and looking forward to comparing rain fall to my cocorah gauge. We have several days of rain forecast so should get a good chance to compare and i will post results here when i get enough comparisons.
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Well i got an hour of slow rain so far and i am comparing it to my eight inch rainwise, six inch commercial, and my davis vp2 gauges. All my gauges showed .06 inches of rain and the rg showed the same. =D> now to see what it does with some heavier rains due in tomorrow. to be continued.
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Got a heavy rain this am and compared the readings. The commercial gauge and the cocorahs got .41, the Davis showed .39, the rainwise showed .38 but the rg 11 only showed .28 :-( :-( So the first results look like the rg is good on slow rainfall but doesnt handle heavy rain very well. Got some more rain forecast the next few days and will get some more results.
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Well got the promised rain and the results for the slow rain are the same as before with all gauges showing within .01 of each other then a few minutes ago got a real downpour and my main gauge showed .72inches which means got .54inch of rain in about 15 minutes. The rg showed .83 which is .11higher this time. I do not know why the last heavy rain was less, the only difference was the first heavy rain was at night and this one was in daylight. I do not know if than can make a difference with heavy rain, maybe it senses heavy rain better in daylight. :?: Well got more rain forecast for end of week will keep looking lol.
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I need to correct the reading from yesterday i compared the reading to my tipping bucket instead of the cocorah gauge and my tb gauge reads slightly low with heavy rainfall. The cocorah had .79 inches and the rg was .87 so only .08 high in heavy rainfall.
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This is my final comment on the rg. The results are not that great so far, this time had lite rain and it read twice as much as the rain gauge and got heavy rain later on and the gauge measured .79 while the rg had 1.23 so no real error factor, just hit or miss i guess. I plan on setting the rg up to sense low rainfall to indicate when i have had a trace to report to cocorahs. We get some sprinkles at times when i am not here or at night and it does not show up in the gauge. We also get fog here that condenses in the gauge and would hide a few sprinkles. The rg never indicated any moisture when we had heavy fog that showed up in the gauges as .01 of condensation so it should make a good trace indicator. I have an old rain counter from the heathkit days that i will hook it upto to give me an indication of trace rain.
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I plan on setting the rg up to sense low rainfall
I think that its usefull for early detection of rain for sure
I have added support for it in weather display now (to do that sort of idea)
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Are your VP2's wireless? You could add a leaf wetness station and sensor to help monitor surface moisture and compaire those values. Just an idea.
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This is another update since my last post. I decided to remount the rg and try again. We just had a severe ts come through with 40 to 50 mph winds and heavy rain for awhile. My two tipping buckets showed .69 and .71 with the rg showing .69 looks good but will need more tests to see if it is just a good run this time or if the remounting made the difference. I had it mounted on a flat surface about 7 feet up and i thought maybe i was getting some splashing from the surface, i had it mounted out on the edge with the mount it came with. Now i have it mount about 4 inches off the ground on a wooden posts to cut down on any splashing. Will post again after the next rain.
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Just got through with some rain and the gr reported .21 which agreed exactly with my cocorahs gauge. My tb gauges showed .19 and .16. Will update next rain event.
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Well finally got some more rain last night and the results were not good. I got .92 inches of rain and the gr showed only .25 inches. It just seems it is not very consistant. Oh well will set it up for trace rain detection.
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Just another update, i changed the tip setting to .0001 per tip and used a dropper to check out how sensitive it is. I get a count with one to two drops , so it should work fine for my trace rainfall alert. I have it mounted and ready to go but no rain forecast for a couple of weeks :sad:. I guess it will give me a good chance to see if it falses any with the setting being so sensitive. To be continued.
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Well finally after a long dry spell we had some light showers around and i had a rain shower that died out with just the high leftover cloud come by and my sensor showed .02 and i went outside and could feel a light misty drop or two on my face. It worked just fine. I would not have know it misted a tad without the indication. =D> =D> =D> So it looks like it will work just fine as a trace rainfall indicator. =D> =D>
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Just a follow up, had a trace indication at 4am this morning. Had the chance for isolated streamer showers and i would not have known if not for the sensor. =D> =D>
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Jerry, do you have a Davis leaf sensor to compare to the results of the RG-11?
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No i do not have one, i never could justify cost versus usefulness. We just had another rain spit and sputter and it indicated /02 so it is working just fine as a trace detector, i am happy with it in that mode.
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Too bad one cannot easily integrate this to the VP2 as rainfall detector.
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Too bad one cannot easily integrate this to the VP2 as rainfall detector.
I did it once as an experiment. Get an anemometer transmitter, set the ID and set the console for that ID as a temp station. Make a cable for the temp/hum jack. I've forgotten the pair that are used for temp.
Connect 2 resistors in series across the temp input. Choose the values experimentally. Set the RG-11 for rainfall detection. Connect the NO relay out of the RG-11 across one of the resistors.
Now, that temp channel will show one temp reading when it's dry, and another, lower one when it's raining. According to the catalog, the extra temps update every 10 seconds, so that's pretty good resolution for "it's raining".
Any weather program that makes graphs will make a "temp" graph that shows when it was or wasn't raining, and if you do any server-side scripting, it would be easy to use the 2 temp values in any kind of display you want.
You could even set an "It's Raining" alarm in the console based on the temperature values.
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with a RG11 connected to WD , WD will set the its raining condition as soon as drops are detected
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How do you get the info to wd?