A manometer may be any device that measures pressure. There are many types of manometers, although the term typically refers to an instrument that uses a liquid column unless otherwise specified. A liquid column manometer uses a tube filled with a liquid to measure the pressure differential between the two ends of the tube. This type of manometer commonly measures the pressure of a gas or the pressure reduction of a partial vacuum. A simple manometer may be built as part of a grade school experiment.
Attach the plastic tubing carefully around the length of the plank using the tube fasteners. Ensure the tubing makes a smooth, even “U” bend around the end of the plank so that the tubing does not become kinked.
Position the plank against a vertical surface, such as a board. Use the plumb bob to ensure the plank is exactly vertical. Hammer a nail through the plank or use some other means to attach it securely to the board.
Pour approximately 100 ml water into the beaker. Add enough dye to turn the water a bright red and mix thoroughly. Pour the water carefully into the tube.
Place a measuring device on the side of the manometer on the opposite end of the expected pressure. Line up the zero point of the measuring device with the surface of the liquid and attach it securely with tape. The measuring device may be a ruler or graph paper, depending on the specific application.
Attach a source of positive pressure to one end of the manometer with an airtight seal. The pressure may then be measured in inches of water.
- pressure image by Dusan Radivojevic from Fotolia.com