New Regulator Advice, Please:

[Menschenstimme]

Many thanks to both of you, David and Pete!!

Obviously, I forgot how to use the water gauge properly! Mea culpa! You are both utterly correct. I was expecting to find 5 inches of pressure and could not understand why I was reading 2-1/2 inches instead. LOL!

Moving along to my next issue: When I tried to read the static pressure of the organ, which is somewhere between 10 and 15 inches, the water just blew out of the top of my gauge and gave me a mini shower. Perhaps I should carefully put in just enough water for the "U" to have room to go down 8 inches on one side and up 8 on the opposite side? Perhaps too little water just blows out and too much water would also overflow, because the gauge needs room to show a differential of up to 15 inches?

[VaPipeorgantuner]

make a bigger loop if you need to measure more wind. Putting smaller amounts of water will not work since the wind is pushing against a lighter load, it will just blow the water out of the tube as before. If you need to measure a pressure of 15 inches (for example) your loops should be 20 inches tall with the water level at just below the middle of the loop's height. And (as a reminder) you read the difference between the water at both the lowest and highest point (or you can measure the difference from the zero-point and multiply by two).

Rick in VA

[Menschenstimme]

Thank you for these additional details, Rick!
Apparently, the "U" should be taller than half the anticipated pressure to provide adequate resistance and the loops should be tall enough to allow the high side room to function without the water overflowing from being blown out.

(I normally go for years without needing to measure wind pressure - otherwise I would buy a mechanical manometer.)

Thanks again!

[Menschenstimme]

Hi again, Rick, et al:

I regret that I need more help. SIGH!

I am trying to use my water gauge and a strange thing is happening regarding the concept that the down side of the water column and the up side should be equal and should be added together. However, I am getting higher readings on the down side than the up side! Is gravity skewing the numbers? My gut feeling is to ignore the down side and simply mutiply the up side times two.

Without going into detail: From what I know about this organ, the inches WC make more sense if I do indeed ignore the down side and multiply the up side by two.

What say you?

Many thanks!

[PeteKnobloch]

It doesn't make sense that one side would not move the same distance as the fluid in the opposite hose. Sometimes an air bubble in one of the lines can cause your calibration point to move. I use a hose that has an inside diameter of about ¼ inch which is large enough to let the bubbles rise quickly in the tube. I also wonder how much precision you are looking for. 1/8 of an inch one way or another shouldn't matter very much but if you just measure the difference between the 2 columns of water, it will be more accurate.

Something else that you must consider is how loud the rank is as compared with the rest of the organ. The people who installed the rank may have thought it was too loud on 5” and lowered it to make it blend better with what was in the chamber. Of course this is very subjective.

[Menschenstimme]

There are no bubbles and my device is in good condition. I can assure you that the difference is indeed happening. The input tube on my gauge is rather long - perhaps about 5 feet. Might this be too much? I am genuinely baffled by this. Thank you for responding!

[davidecasteel]

If the bore of the gauge tube is not uniform, you could get unequal readings. If the bore is quite small, I suppose that surface tension could make a small difference. A long input from the chest to the gauge would drop the pressure somewhat, but it should affect both parts of the water column the same. I believe I would measure the full distance between the two stable water levels under pressure. Also take care to put your eye at the same level relative to the meniscus on each side.

David

[Menschenstimme]

Thank you, David!

My manometer does not look like a maximum accuracy unit. It is well made - but probably was a home-made device. The actual "U" at the bottom of the two glass tubes is some kind of transparent plastic hose. Theoretically, there should be no differential between sides - so something about this device is just not quite right.

I will experiment with it some more. But I will have to wait for my friend's Dwyer unit to complete my task(s) correctly.

Thanks again!

P.S.: It has been about 35 years since I have heard or seen the word "meniscus." SIGH!

[davidecasteel]

The more I think about, the more it seems that bore equality ought not to be a factor--only the difference in "head" should matter. The possibility of surface tension effects does still exist.

Relative to "meniscus"--I find that I quite often use words that are uncommon; I guess it's just the way my mind
works.

David

[PeteKnobloch]

I deleted the text from my last post (this post) because it was just wrong. Don't want to confuse the issue. I was wondering how much is your measurement off between the water in the left column and the right? Are we talking 1/8 inch? And what is the inside diameter of the water columns? It just doesn't sound right.