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Re: Hydreon RG-11 results

Posted: Sun 08 Jul 2012 9:17 am
by duke
bruce45 wrote:
hi dont no if this will help its from there site as to how the rg11 works


The RG-11 bounces beams of light within the lens. When drops hit the outside surface, it allows some of the beams to escape. The RG-11 detects the change in beam intensity, and determines the size of the rain drop that caused the change.

Would "beams of light" not suggest they are capable of monitoring the larger surface area and not just the 4 points?

Do two of the points not emit the beams and the other 2 points receive the beams and therefore again suggest monitoring the larger surface area and not just the 4 points?

If I get 5 minutes today I'll set it up on the bench and drop a drop in the highest point of the dome but, I don't have much time for "playing" today :(

Re: Hydreon RG-11 results

Posted: Sun 08 Jul 2012 9:38 am
by bruce45
Alan

the surface area of the rg11 is about 75 square mm

so for the same area works out about 10cm diameter circle

the diameter of the rg11 is about 7cm

just thought the figures might help

Re: Hydreon RG-11 results

Posted: Sun 08 Jul 2012 9:52 am
by bruce45
Duke

this is also from there site as to how it works
how_rg-11_works.png
i am going to try dropping water on areas and see if there is anything else

Re: Hydreon RG-11 results

Posted: Sun 08 Jul 2012 10:32 am
by duke
Thanks Bruce, I'll bekeeping the ipad at hand to monitor your results. But, from that image, it suggests that the beam being broken anywhere on the dome should cause a trigger.

Re: Hydreon RG-11 results

Posted: Sun 08 Jul 2012 10:45 am
by bruce45
just been using a 5mm syringe to drop water over different areas.

as it is quiet where i live i could hear the relay operating so no need to have to keep checking cumulus.

there is only the 4 areas that cause a response. over the screw fixing areas nothing,on the very top of the dome nothing its is only when the drop is large enough that gravity causes it to run off that it respondes, as long as it goes over one of the 4 areas. there is fitted a shade protector to stop unwanted ir light and restrict the area.

not really sure were we go from here

Re: Hydreon RG-11 results

Posted: Sun 08 Jul 2012 12:11 pm
by bruce45
this is a screen shot from select a graph

not sure what happened at 7am reset cumulus about 10am

the traces are much the same apart from that
rg11.jpg

Re: Hydreon RG-11 results

Posted: Sun 08 Jul 2012 12:13 pm
by apenwith
Hi
Experiment 2
DSCF2039.JPG
The curious addition causes two series of drops falling roughly over the masked (sensor) areas.
The results were interest if not terribly informative at this stage. A full 25mm of 'rain' actually recorded 33mm (the first time I've seen an over-read). But oddly 5mm rain recorded at 10mm. I don't know if it would be regarded as valid but using a factor of 0.7 puts both readings within 2mm. I have not yet tried really small quantities and the experiment was done by filling the funnel with the full quantity whereas rain would be more gradual. For real rain I'll have to find a way of screening the RG so it does not receive direct rain.
Regards
Alan

Re: Hydreon RG-11 results

Posted: Sun 08 Jul 2012 12:19 pm
by apenwith
Hi
Looking at the select graph could the Cumulus reset (restart?) have put in the extra tip (that depends on the tipsize used). Just re-read and the reset was 10am - maybe a bird sat on the RG :lol:
Alan

Re: Hydreon RG-11 results

Posted: Sun 08 Jul 2012 12:30 pm
by bruce45
Alan

from my drip tests using a syringe and the rg11 test program that Steve did i noticed that a single drop which runs over the area caused more on/off switches. tried with two areas together and only got one set of on/off. so i think that if the rg11 has detected rain and is operating the relay when another drop lands on the area it misses it. where as if the rain drop runs over the area it can count it more than once. depends how fast it runs off. it did not matter if the drop was over either of the diodes or over the ir detectors. when i tried the two drops together i tested both on the diodes and the detectors as well as one drop on a diode and one drop on the other diodes detector but it was the same result.

wife thinks i have totally lost the plot and gone back to bed. kids just say i lost the plot years ago.

bruce

Re: Hydreon RG-11 results

Posted: Sun 08 Jul 2012 5:22 pm
by apenwith
Hi
I now have a rain protected version of the RG with Funnel - involving plastic drain pipe and messy silcone sealer but at least the rain can't fall directly onto the RG. I tried a test with a hose sprinkler but it is very difficult to get consistant 'rainfall' on both the RG and the manual gauge so we wait for real rain. Probably not that long this glorious July.
Alan

Re: Hydreon RG-11 results

Posted: Sun 08 Jul 2012 7:02 pm
by apenwith
HI
so i think that if the rg11 has detected rain and is operating the relay when another drop lands on the area it misses it
I don't think that is right - the drops are counted individually and the count operates the bucket. I reckon it would need 720mm/hr rainfall to get close to that happening and then only with a very small bucket size. 720/3600 =0.2mm per second 0.2mm / 20 =.01mm per 50ms
Regards
Alan

Re: Hydreon RG-11 results

Posted: Sun 08 Jul 2012 8:46 pm
by bruce45
apenwith wrote: the drops are counted individually and the count operates the bucket
not sure where you found this info. it was a theory in an over post i think.

hydreon site claim

The RG-11 bounces beams of light within the lens. When drops hit the outside surface, it allows some of the beams to escape. The RG-11 detects the change in beam intensity, and determines the size of the rain drop that caused the change. The sophisticated circuitry and Digital Signal Processing detect tiny rain drops, and reject the effects of ambient light disturbances.

nothing to do with counting

i have my rg11 set dip switch 1 on 0.001 inches

the test i did with the syringe every time a drop landed on the area the relay operated, could hear it operate, but more drops on as a stream of water still only one operation. drying the dome with kitchen roll after each test operated the relay.

it would seem that there is a set amount of light emitted from the diodes and the ir sensors look for the change in light. more defraction more rain.

thats how i came to the conclusion with the drop test 5ml syringe gives about 50 drops with light pressure so each drop would work out the correct size to trigger the cct to send the tip for 50ms. if there was another drop of the same size when the relay is operating why should it report it. it has already reported the rate.

its like the tip bucket pour water into it at a fast rate and it stays tipped on the same side.

this was tested with the rg11 test program and not with cumulus. it was to find the areas that detect rain.

Re: Hydreon RG-11 results

Posted: Mon 09 Jul 2012 2:59 am
by pete_c
I had a bit of rain today July 8, 2012. Here are my results

Cumulus via Davis Vantage Vue Tipping bucket - 0.13 in (note that the Davis instrument is not adjacent to other 3)
Cumulus via RG-11 - 0.34 in
Dallas Tipping bucket - 0.11 in
RG-11 via 1-wire Dual counter - 0.13 in

Re: Hydreon RG-11 results

Posted: Mon 09 Jul 2012 7:46 am
by apenwith
Hi Bruce
I can see that with such a small tip unit it would not take many drops to trigger the relay but mine is set to 0.2mm and that takes a number of drops to operate the relay so they must be counted or the volume calculated somewhere.
Can I ask if Bruce is a family name - my ancestor Bruce's hail from Thurso and Orkney.
Regards
Alan

Re: Hydreon RG-11 results

Posted: Mon 09 Jul 2012 7:50 am
by apenwith
Hi Pete
Did you check the debug log to see if Cumulus RG had any double tips
Regards
Alan