Rain GaugeDelema

With all of the talk of recent rains, a close friend of mine  has always used a tapered/funnel shaped gauge that will hold roughly 4"s of rain for at least 15 years with no thoughts on accuracy/inaccuracy until his wife brought home a new gauge from the local flower/garden center and set it 3 feet away from the "original". The new one is a 2 1/2" straight cylinder that reads consistently 1/2" more  than the original . I would like to know if/what is a test to verify which unit is correct . My first thought was to put 1"(measured with a tape measure) in soup can and dump that amount into each gauge in question, but am pretty sure that experiment would be skewed ?? Thanks

Thanks, I had a felling it wasn't going to be a "simple" experiment LOL!! I think I will suggest to him to get a third gauge and average them out .

I'd like to have two things at the farm house. A thermometer and a rain gauge, both in orange. Repop would be fine with me.

If you use the same amount of volume, in each rain gauge should read the same. Put a 4 or so ozs. in each and check it.

It doesn't matter the shape or size. Volume is volume. The calibration on the gauge is what changes. The scale in which it reads. Tracy

Volume is volume. The shape and size determines the level at which they fill. It is the calibration on the rain gauge itself, that changes to read the given amount in each of the said rain gauges. Tracy

I get that! Umm......you have a good one sir.

Take a soup can and fill it with water... Call that 4 inches of rain.............. Now pour that full can into a 5 gallon bucket and tell me how much " rain" you have.

You guys are missing the point. Volume is volume. It is the scale on the gauge that has to compensate for the different  sizes  of rain gauges. If both gauges will hold at least the volume you want to check, it doesn't matter the shape or size. It is a scale that reads the amount of volume. Each scale will be different spacing, but the volume should read the same. HTH, Tracy

After the second wettest May in record does anyone know where I can get a 10” rain gauge? Getting tired of pouring it out while it’s raining to keep up an accurate reading lol

Tracy Martin TN wrote: You guys are missing the point. Volume is volume. It is the scale on the gauge that has to compensate for the different  sizes  of rain gauges. If both gauges will hold at least the volume you want to check, it doesn't matter the shape or size. It is a scale that reads the amount of volume. Each scale will be different spacing, but the volume should read the same. HTH, Tracy

Tracy, think about this:

Let's assume 1 inch of rain fell as an accepted fact. You have a 5 gallon bucket sitting there, put a mark on the bucket, and call it 1 inch. A bucket is slightly conical shaped, so with a tape measure, it won't read an inch, that's where calibration comes in. Each time from here forth, whenever that bucket collects water to that mark during a rain, an inch of rain fell.

Next, you want to make another gauge. This time you make it out of something totally different, like a soup can. You can't take the rain from the bucket and pour it in the soup can and make your mark, because the mouth of the bucket would have collected way more rain during the rainfall. You'd have to have them both out in the rain, and when the bucket gets to it's mark, go mark the soup can. A fixed volume cannot be used to compare the two scales.

My last thought experiment for you. After this, I give, I really meant it this time

Tbone95 wrote: Tracy, think about this: Let's assume 1 inch of rain fell as an accepted fact. You have a 5 gallon bucket sitting there, put a mark on the bucket, and call it 1 inch. A bucket is slightly conical shaped, so with a tape measure, it won't read an inch, that's where calibration comes in. Each time from here forth, whenever that bucket collects water to that mark during a rain, an inch of rain fell. Next, you want to make another gauge. This time you make it out of something totally different, like a soup can. You can't take the rain from the bucket and pour it in the soup can and make your mark, because the mouth of the bucket would have collected way more rain during the rainfall. You'd have to have them both out in the rain, and when the bucket gets to it's mark, go mark the soup can. A fixed volume cannot be used to compare the two scales.  Volume is volume. If you had exactly 3 ozs of water in two different rain gauges, one straight sided and one tapered it is still 3 ozs. Each gauge will need a different graduated scale. The straight side one will have equal division  increments on it's scale. The tapered one will have wider marks at the bottom and as it rises the marks will be closer together, to compensate for the taper.  I am not sure what you thought I was describing, but my intentions was this. HTH Tracy My last thought experiment for you. After this, I give, I really meant it this time

Just get an electronic one make sure it's level where you have it and it'll continuously empty it's self. Don't even have to got out and check it. Can also get wind speed and direction temp and humidity without even looking outside. You can have three identical rain gauges set in three differant places in the yard and you'll get three differant readings. I had two of the funnel top gauges set 150' apart. One in he garden one outside my living room. Both in open areas they were always 1/2" apart. Since they were the exact same guage I swapped them they were still 1/2" apart. The living room one always was more than the garden. Unless I had been watering that day then the garden was of course more since it also captured the sprinkler.

It's just as accurate as anything else. Take several straight sided 5 gallon buckets set them around your yard in various places. After a good rain fall measure each one with a tape measure. There not going to be the same so which one is accurate. They all are except the one you placed close enough to the barn so it gets roof runoff. I replace the batteries in each of my electronic gauges every two years. They don't change measure amounts until after the remote battery low indicator comes on For a couple weeks then they stop working. The most accurate is the straight sided 5 gal bucket. It captures the largest sample.