Here is a demonstration to measure the increase of pressure with the height of a liquid:
Build the set up for a lab ! Is there a linbear relation ship between the depth of the funnel and the height of water
in the U- tube? Build a table . X = depth in cm of the funnel = independent variable
Y = height of rising water in the U-tube = dependent variable. Plots The dots (X,Y) on a graph paper and see if you
have a relationships between the variables. (source)
Measure pressure in liquids with a U-tube
Half fill a U-tube with colored water. Stretch a piece of thin rubber loosely over the mouth of a filter funnel and tie it securely. Attach the stem of the filter funnel to one arm of the U-tube with rubber tubing. Hold the mouth of the filter funnel at different depths in a container of water. Record the depths of the mouth of the funnel in the water corresponding to the differences in heights of the colored water in the U-tube. This U-tube is being used as a pressure gauger.
1) Cut one end off a tall plastic drink bottle to make a tall container. Use the pressure manometer from the previous experiment. Place the funnel at different depths to measure the pressure. 2) Repeat the experiment with a container of methylated spirit, pure water and salt water. Hold the mouth of the filter funnel at the same depths in the three liquids and note the corresponding differences in the heights of the colored water in the U-tube. At the same depth, the less dense methylated spirit exerts less pressure than pure water and the more dense salt water exerts more pressure than pure water. 3) Repeat the experiment using a large container of water and a small container of water. Hold the mouth of the filter funnel at the same depths as before. The corresponding differences in height of the colored water in the U-tube are the same.