i want to build a weather station and was looking for rain gauges.
All of the affordable ones are tipping bucket systems.
But i realized some problems with this system.
counter weight not always the same
at the end of the rain it stops before filling for the last time so there is water left in one bucket
So i had the idea to count drops and after researching i found this one:
If you can organize for the drops to break a light beam between an LED and a photodiode that would probably be simplest - no contact and no contamination.
I presume you will have a reservoir to hold back heavy rain and allow it to feed as a series of drips. This will mean the drips continue long after the rain has stopped - though it should give you the proper total volume.
What about making your own tipping bucket with a very small bucket fed by a large collector. The advantage is that it allows you to detect the rate of rainfall.
Or you could have a loadcell to weigh the water in the bucket (any size of bucket) and it could empty the bucket when the load exceeded X. That way it would not matter if the rain stopped with the bucket partly full.
not sure of the application. a rain gauge is just an approximation of the rain. based on a very small sample area, it offers a huge variation of real world rain volume.
rain falls in sheets. a sheet of rain could dump 1 gallon an hour in one part of your lawn and a gap between sheets could dump 1/2 of that.
if you look at a tipping bucket, you have a way of putting your rain flow into a volumetric reading.
before getting into reading drops, you might be well served to place a hundred collection cups over an acre and then read the variance.
also, the tipping bucket value is based on the square area of the opening and the volume of the bucket.
a larger area, and a smaller bucket will yield greater accuracy.
I would offer that before you try to measure into the multiple decimal places, you evaluate the actual process to determine what the reading will actually represent.
bty, if you get home heating duct filter, the cheap stuff, you can cut that and put that into the cup and greatly reduce splashing.
you can put these in the yard and measure how evenly your sprinkler delivers water.
The first guy writes that polycarbonate does not interfere and in the second link you
can see in the images that he also has the IR through the hospital IV bottle thing.
I guess from the images that the sensor has like 4 needles and the thing that makes
the drops are built in cause the sieve on top is a big opening and there to prevent leaves
and dirt coming in.
So a funnel on top and the circuit in my attachment should work?
The green, blue, red and orange line is the water drop.
So no matter where the electrical short is it should count.
I have now 3 different water sensor circuits (attachment) - The one with CD4093 switches on if it gets dry.
Not sure which one is the best.
First i wanted to make it standalone but i have other stuff too so it would
be nice to connect everything to one Arduino in the garden shed.
That means 5-10 meters (19-32ft) and i want to use CAT6 cause
then i can put 1Wire and the water sensor in one cable.
So 12 volt would be best i guess that i don't loss to much power on the thin cable.
Also it would be best if the two sensor wires go from the garden shed to where i need them.
This way i save strands in the cable and can use twisted ones to increase the cross section of the wires.
Ideas, tips, hints?
Or would optical detection be better?
