Simple U-Tube Manometer

It is a manometer that has a fluid reservoir and the end open to atmosphere. It is common to have two different type of fluids within the manometer, one fluid in the reservoir, and another type of fluid within the U.

How to get this equation?? 

From,

 

Then, we get,

 

credit to: http://sbainvent.com/fluid-mechanics/manometer.php#.UKwtKWXVFsg

How to calculate pressure in manometer

Piezometer


A piezometer tube is the simplest monometer that can be used. It consists of a fluid reservoir and a tube opened to atmosphere.

 

How to get this equation???

From

 then become

credit to: http://sbainvent.com/fluid-mechanics/manometer.php#.UKwtKWXVFsg