Weather Station Hardware > Rainwise Weather Stations

RW 8" tipper

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DaleReid:
I may have been mistaken on the rain gauge in the wind shield.  It may be a NovaLynx, but essentially the same as an RM  Young.

DaleReid:
You may have been doing it right, but using erroneous values given to you by someone who should know better.

Not as bad as crashing a multi-million dollar Mars Probe because of a calculation error, but you know the feeling.

My guess is that the best would be to hope for a long slow drizzle rain some time (we've not had one in years here, very disappointing, they are great to sleep to) but only the monsoon deluges that have been short and far between, and see what you gauges show.  A neighbor who is retired had a whole flat area full of cheap and expensive tippers, CoCoRaHs and other high quality stuff that was collectors all within a 15 foot radius.  All summer (rainy_ long he laboriously took and recorded measurements.  To have them within a few 0.01" was rare and one confusing storm he had one of them off by TENTHS of an inch, while they had previously been pretty much spot on.  No sign of a squirrel or dog peeing in one, either.  Strange things happen.

I'm thinking you can have fun this summer between storms running a half dozen volumes through the tippers to see how they come out, based on your measurement of the throat and the recalculation of the volume needed, then weighing the water rather than using a kitchen appliance to get the volume.  The final and likely frustrating thing would be to use an eye dropper or syringe from an animal supply store to count the drops needed to get each side to tip.  Once you start trying to adjust one a little bit, that will throw off the whole calibration, so the other side will need tweaking.  Nonetheless, the Novalynx chart will help.

Good luck.  And pay no attention to the guys who have their unit nailed to the top of an unlevel post and compare to the TV station a couple miles away.

Enjoy the fun.  Dale
As my wife says, it keeps me out of the bars.

CW2274:
My data has been collected over many years. I've calibrated both tippers dozens of times just to be sure they are as good as they can be over the years. All my calibrations are done by weight with a scale that is checked for accuracy, every time. It is empirical and consistent, once again, within reason. You answered the question I was most concerned with, what is the correct amount. RW should be taken to the tipper woodshed for this. Unacceptable.

Thank you again for you time.

Cutty Sark Sailor:
As Dale, et.al have mentioned...
A lot of confusion may track back to an error reflecting the exact inside 'diameter' / radius / volume of the collecting cylinder. Just because it advertises 8 inches may NOT reflect the truth. I know fellows who are famous for such.
Also, water is at maximum density at 4°C - .99997 gm/cm3. Becomes slightly less dense as temp increases / or falls until frozen. And  variations in air pressure changes decimal slightly. We'll ignore the pressure.

1 inch = 25.4 mm, and since the density of liquid water at varying "livable" temps might be considered insignificant, then "1 inch equals 2.54 cc=2.54ml= ±2.54gm (per temperature: 50°C= 0.998cm3 or 2.535 gm).
An 8 inch inside-diameter cylinder 1" tall should have a volume of 50.265 in3, or converting to metric,
it is a 20.32 cm diameter 2.54cm tall cylinder ( a radius of 10.16 cm) = 823.7 cm3 volume x .99997(4°C) = 822.975 gms

So, (KISS), if my 8 inch gauge does NOT decant ±823 gm per inch at 4°C (822gm @ 122°F / 50°C) ... then
1. it isn't an 8" inner diameter gauge.
2. my rain isn't pure water (ridiculous example: 'Heavy Water' masses about 11% greater)
3. the scale isn't accurate
4. the rain is extremely warm
5. the air pressure is absurd
6. I goofed up the decant
7. I assume that a gauge marking of one inch is accurate, when in fact it may not be, and eyeball and advertised dimensions don't correlate with math.

If a manufacturer specified an 801gm per inch reference, then that reflects an inner diameter of about 7.89". And if their measurement markings are actually calibrated for a (7.9") cylinder, then what's the problem?....
...there is none on the eyeball method... or on the 'weight' method... IF the right baselines are observed.   

Properly marked and calibrated gauges of real 8" compared to a misrepresented but accurately calibrated 7.89" gauge will SHOW identical collection values, but WEIGH different masses!

 This of course completely ignores calibration or accuracy of any tipping / electronic device recording such input. Collect it with bad advertising, then you get what you get.

CW2274:

--- Quote from: Cutty Sark Sailor on January 24, 2024, 09:15:14 AM ---If a manufacturer specified an 801gm per inch reference, then that reflects an inner diameter of about 7.89". And if their
measurement markings are actually calibrated for a (7.9") cylinder, then what's the problem?....

--- End quote ---
Ummm, what? What measurement markings? It's a tipper. All I wanted to know is the figure of 801 or 824 accurate for this tipper, which I measured the collector diameter, and it's exactly 8", maybe a hair over. Your over-the-top explanations are nothing more than subterfuge AFAIC. I'm going to redo the calibration at 824, as Dale and NovaLylx state.

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