Rain Guage Design

[Running Arrow Bill]

This is question for the Mathematicians, Engineers, Physics people:

What is the "Ratio" of the inlet collection opening to the diameter of the rain tube, to the inch measurements on the collection tube? (To get an accurate measurement of rainfall).

Am sure there is a very logical set of specifications here...

Thanks,
Bill

 

[backhoeboogie]

They call them standards. My books are at work. If you are googling, use the term standards.

 

[cfpinz]

Maybe I'm missing something here but it seems like it should be a ratio of the collection area to the holding area. Area of a circle is 3.14(r*r), r being the radius of the circle. If the funnel has 30 sq in of face area and the collection tube has 10 sq in, it would take 3 inches in the tube to make one inch of rain. Clear as mud?

cfpinz

 

[backhoeboogie]

Maybe I'm missing something here but it seems like it should be a ratio of the collection area to the holding area. Area of a circle is 3.14(r*r), r being the radius of the circle. If the funnel has 30 sq in of face area and the collection tube has 10 sq in, it would take 3 inches in the tube to make one inch of rain. Clear as mud?

cfpinz

Heck, for that matter you could do something as simple as putting a funnel on your tube, get a seperate graduated cylinder, put in a quarter inch and a time and mark the tube.

I think he is looking for the accepted standards.

 

[Caustic Burno]

This is question for the Mathematicians, Engineers, Physics people:

What is the "Ratio" of the inlet collection opening to the diameter of the rain tube, to the inch measurements on the collection tube? (To get an accurate measurement of rainfall).

Am sure there is a very logical set of specifications here...

Thanks,
Bill

They sell them at walmart for 3 bucks.

 

[Running Arrow Bill]

This is question for the Mathematicians, Engineers, Physics people:

What is the "Ratio" of the inlet collection opening to the diameter of the rain tube, to the inch measurements on the collection tube? (To get an accurate measurement of rainfall).

Am sure there is a very logical set of specifications here...

Thanks,
Bill

They sell them at walmart for 3 bucks.

LOL Caustic

Not that I had, have any intentions of "making" a rain guage... I was just curious about the design and ratios or whatever that they come up with...

 

[KenB]

I think the most accurate, and the most used are straight sided.
If an inch of rain falls in it it will measure 1 inch.
If the gauge is tapered it will vary with the amount of taper.