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Miscellaneous Debris => Weather sensors, design, analysis, discussion, home brew => Tech Corner => Rain Gauges => Topic started by: SLOweather on November 16, 2016, 03:09:50 PM
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Many moons ago, I was a wastewater treatment plant operator for the City. (I still have my Grade 5 Operator's Certificate.)
I also ran a couple of small plants on the side, and still have my lab kit.
On TV a while back, I saw a beer commercial where the brewmasters were drinking out of a couple of pieces of lab ware called Imhoff cones. In wastewater we use those to measure settleable solids, generally in raw influent and finished effluent. Presumably, they are used for a similar purpose in beer making.
Anyway, I got my kit out and retrieved a cone and stand.
(http://www.sloweather.com/blog/2016/161116imhoffcone.jpg)
It has the exact same top diameter as a Stratus gauge. Calculations say (if I remember correctly) that 2 ml = 0.01".
I think I'll stick one out in the rain and see how it compares.
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I wonder if it would be less susceptible to splash-out than a conventional gauge. You might have an idea here...
Greg H.
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I wonder if it would be less susceptible to splash-out than a conventional gauge. You might have an idea here...
I hadn't thought of that...
And in theory, I think you could use a Stratus inner cylinder to measure it if desired.
It also reminded me of a "remote" rain gauge someone had a long time ago that was a funnel on the eave of the house, with small tubing leading to the measuring cylinder in the house. This would be a great funnel for that. The tip has a screw cap for cleaning.
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Calculations say (if I remember correctly) that 2 ml = 0.01".
In my best Phil Hartman doing Ed McMahon impression, "You are correct, oh mighty one!"
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It also reminded me of a "remote" rain gauge someone had a long time ago that was a funnel on the eave of the house, with small tubing leading to the measuring cylinder in the house.
what a neat idea, lol
you would want to empty it regularly?
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We had rain last Sunday.
(http://www.sloweather.com/blog/2016/161123imhoffcone.jpg)
The Stratus measured 0.98", the Imhoff cone, 0.96" (as measured using the Stratus inner cylinder). I probably waited too long to measure, and, pending further results, am chalking up the difference to 3 days of evaporation.
I did check the cone when the rains first started and it's easy to read the accumulation in the tip down to 0.005" (1 ml) or even less (well before any of the tippers registered).
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We had rain last Sunday.
(http://www.sloweather.com/blog/2016/161123imhoffcone.jpg)
The Stratus measured 0.98", the Imhoff cone, 0.96" (as measured using the Stratus inner cylinder). I probably waited too long to measure, and, pending further results, am chalking up the difference to 3 days of evaporation.
3 days? I would lose that much here in 3 hours. :-)
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...and THAT is why most of Cali-prunia is green and most of Arid-zonia is brown (wink,wink)