# Brain not working on this problem

1. Jul 18, 2006

### wxrocks

I am working on a repair for an old Meriam Well-type manometer and I am being a bit lazy on thinking/writing out my problem. I am trying to design a new well for it.

My question is -- am I right in thinking the well should have a large diameter and a low height so that the fluid pressure won't affect my readings much? Meaning, if I made a smaller tank and had a long tube out the bottom and had it loop back up to the manometer, the fluid pressure would "push back" on the well, thus it would take more "real pressure" before I got a reading -- or in other words my readings would be low????

The fluid has a specific grav of 2.95, so it is fairly "heavy"

Thanks!

2. Jul 18, 2006

### Danger

Since I have no idea what you're talking about, could you express the question in layman's terms? I don't know what a 'manometer' is, or what a 'well' has to do with it. If you tell me, however, I might be able to help. (And yes, I know that it sounds stupid, but sometimes it works for me.)

3. Jul 19, 2006

### wxrocks

Here is a picture of a well manometer. Obviously, it works much like a u-tube in that you are measuring the weight of the fluid in the tall tube, and thus the pressure at the bottom. The well is where the (in this case) air pressure is applied, pushing the fluid in the well down. The well level needs to change little to make it negligible. If it chaged more (such as if the tank were smaller) then my "zero" on the other side would change and I would need to measure more fluid in the tube to get a true pressure reading.

I just want to verify the physics on the "well" side. I get it now -- by looking at a book that had examples of the pressure at various points in the system.

Thanks!

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4. Jul 19, 2006

### Staff: Mentor

Danger does it again! Man, he's good.