Q&A for How to Build a Rain Gauge

I'd say it does because if the diameter is too large, the funnel will extend deeper into the bottle, and you'll have less room for measurements. if the diameter is too small, the funnel may not fit.

If the rain gauge leaks you can always re-make it. If you do not want to redo the whole rain gauge, you can simply dump the water out and tape the parts that leaked using waterproof tape.

No, the bottle is made of flimsy plastic that will likely just melt if you attempt to heat it. You would need a higher grade plastic to do so.

There is no string needed for these methods. You will just need a bottle, some tape, and something to hold it down (pebbles).

Scroll down to the bottom of the article to the "Things You'll Need" section. The materials are pretty simple. If you use "Method 1" you will need: an empty two-liter plastic bottle; scissors; a few handfuls of clean pebbles, gravel, or marbles; duct tape; a ruler; and a permanent marker.

Use a precision or utility knife, or a pair of scissors. If you are a child, have an adult do it for you.

You can use as many or as few as you would think would be required to keep it steady in inclement weather. It would also depend on the size of the pebbles, so there is no set number.

You don't have to, but it would be easier to use a big bottle so that it can hold a substantial amount of rain. Smaller bottles will not work well for this task.

I wouldn't recommend using a milk carton since it's opaque, which means you can't see through it.

Yes, but make sure the gauge is on the opposite side of the handle.

You can use other small materials, like gravel, to hold down your gauge. Otherwise, you can use a large amount of beads. I don't recommend that, because you'll have to change your measurements.

It is not possible to lower the rain gauge when using a soda bottle because the bottom of the bottle is uneven. The only way you can lower the rain gauge is if you cut the uneven part of the soda bottle.

That's why you place the "zero" mark of the gauge above the stones and fill the bottle with water up to the "zero" mark before you position the gauge, so you're measuring only the water above the stones. See Method 1 Step 4 above.

Place heavier stones in the bottle, or dig a small hole and place the bottle partially into the hole, firming the soil around the bottle. (In this case, you may have to remove the bottle from the hole in order to read the gauge.)

That depends on your weather and on how long you plan to go between the times you empty the bottle. Five or six inches would probably be enough, unless you live in a very rainy area.

Yes. Sand or gravel would also work.

Actually, no. If the gauges are installed very close to each other, they'll both show a water depth of 50 mm. The reason is that although the larger gauge needs more water to cover its floor to an equal depth, it also has a proportionately larger opening at the top so it can gather more raindrops.

They're for ballast: it's weight to hold the bottle upright when the wind blows.

It's not a critical measurement. Somewhere around two or three inches will work fine.