Manometer

cArNaGe · Post by **cArNaGe** » Sun. Oct. 05, 2008 12:26 am

Inches of water or Inches of mercury.

Water right?

Why use a manometer and not a vacum guage? Is it because of being able to zero it?

Matthaus · Post by **Matthaus** » Sun. Oct. 05, 2008 12:53 am

A vacuum gauge doesn't read low enough (reads 0 to 30" of mercury.

inches of water at 4 degrees Celsius (4oC) x 0.07 = inches of mercury

Simply put you would be reading in the .001" scale on a mercury reference device. Trust me you want a manometer reading in inches of water to measure draft.

Yanche · Post by **Yanche** » Sun. Oct. 05, 2008 12:55 am

You can use a vacuum gage. It costs a lot more, is usually not as accurate unless it's laboratory quality and it's no where near as rugged. Measurements are in inches of water.

cArNaGe · Post by **cArNaGe** » Sun. Oct. 05, 2008 2:23 am

I have a DWYER Vacuum Gauge Model 2005

http://www.dwyer-inst.com/Products/Product.cfm?Gr ... Name=Specs

It reads 0-5" of water.

Or should I just by the Manometer.

LsFarm · Post by **LsFarm** » Sun. Oct. 05, 2008 4:11 am

If your gauge is the one pictured in your link,which is a 0-1.0" scale,, a normal draft for a chimney would be in the first section, 0-.1" normal is around .04-.07" or in that range. The meter pictured is the meter that will be used in the loaner manometer program this season.

If your model 2005 does not have a scale at least as expanded in the 0-.1" range is will be difficult if not impossible to get a usefull reading.. you will be trying to read an indication the width of the needle.

Greg L