Handy rain gauge cal/checker.

[DanS]

This cheap an easy "high tech" rain gauge calibrator/checker works great. I saw the $135 dollar ones on the net and thought I could make one to see if it really works. It does and soooo much easier than trying to pour water through yourself. Find a plastic baby bottle with the most detailed measurement scale you can find. Take the rubber nipple and trim the bottle seal portion off and save for a washer. Take a soft, flexible piece of plastic like from a butter bowl lid and cut a disk out of it to fit on top of the bottle. Poke 2 tiny holes in this disk off center from the middle (this off center approach keeps the dripping out of the center of the gauge's funnel). Hot glue a plastic straw to one of these holes and trim the straw so it doesn't hit the bottom of the bottle. Put the disk/straw assembly in the bottle lid with the rubber nipple washer after. The DVD case lid gets a hole cut out in the center so it fits over the bottle top and the lid secures it firmly in place. Fill with water to the amount you want to measure on your station, screw on the lid and set in on the gauge.  Note: As you flip over the bottle do it so the straw end gets air to clear the straw of water. It flows smoothly this way.  Pat yourself on the back for just saving yourself about $133. My bottle even came with something you won't get from those more expensive dealers, a Winnie the Poo decal!  oh, and the DVD lid is just under 5" round so it fits over 4 1/2" round gauges and sits nicely inside the top of 8" funnels.

[Downlinerz2]

Dan,
   Well done !! It's accurate, frugal, and usefull.  What's not to like?!?!  Going to give it a try this Spring. 

[W3DRM]

Perhaps I am missing something here but how do you know exactly how much water to put in the baby bottle? An inch of water in the baby bottle, which is smaller in diameter than the rain gauge collector funnel, doesn't necessarily mean an inch of water read by the rain gauge. It would have to be calibrated based on the diameter of the rain gauge collector funnel. Guess I am just confused on what formula was used for this project.

[tomcj2]

I found the easiest way to measure the water was by weight.  The Davis rain bucket has an area of 33.2 sq in, so an inch of rain would require 33.2 cu in of water to pass through the opening of the funnel to the tipping buckets.  33.2 cu in water weighs 544 grams.  I used 1/2 of that ( 272 grams)because of the volume limitations of my container and calibrated until my VP2 read .5 in.  If you do not have a kitchen scale, 272 g of water equals 272 cc which equals 9.2 fluid ounces (US).{ there is a difference between a US and an Imperial fluid ounce}

(edited because I initially stated the VP2 area to be 32.2 sq in)

[DanS]

Perhaps I am missing something here but how do you know exactly how much water to put in the baby bottle? An inch of water in the baby bottle, which is smaller in diameter than the rain gauge collector funnel, doesn't necessarily mean an inch of water read by the rain gauge. It would have to be calibrated based on the diameter of the rain gauge collector funnel. Guess I am just confused on what formula was used for this project.

All the formulas and equations used, http://www.wxforum.net/index.php?topic=6042.15 

[DanS]

I found the easiest way to measure the water was by weight.  The Davis rain bucket has an area of 32.2 sq in, so an inch of rain would require 32.2 cu in of water to pass through the opening of the funnel to the tipping buckets.  32.1 cu in water weighs 544 grams.  I used 1/2 of that ( 272 grams)because of the volume limitations of my container and calibrated until my VP2 read .5 in.  If you do not have a kitchen scale, 272 g of water equals 272 cc which equals 9.2 fluid ounces (US).{ there is a difference between a US and an Imperial fluid ounce}

That's a good idea too, like a postal scale for weighing letters. Same process but a different way of measuring the quantity of water. I'll have to try that and compare the results. (can you tell I'm bored and have little to do?).

[sam2004gp]

.... (can you tell I'm bored and have little to do?).

I got some house cleaning you can come and do.

[DanS]

.... (can you tell I'm bored and have little to do?).

I got some house cleaning you can come and do.

Appreciate the offer Sam but I believe you'd probably prefer one of Lars' housemaids to do it for you instead.

[SlowModem]

Appreciate the offer Sam but I believe you'd probably prefer one of Lars' housemaids to do it for you instead.

Some of Lars' housemaids

(it's difficult at times being a double-naught spy)