# What is a Manometer & How Manometer Works? Manometer is an instrument for measuring the pressure acting on a column of fluid that consists of a U-shaped liquid tube in which the liquid rises to various heights in the tube arms due to different pressures acting in the two arms of the tube.

The manometer was invented by Otto Von Guericke, a German scientist. The main purpose of the manometer is to measure the pressure present in a pipeline. This article discusses the manometer, how to build it, and the working principle.

## What is a manometer?

A manometer is defined as a device that is used to measure the pressure in a fluid using fluid dynamics. The fluid can be in the form of a gas or a liquid. Manometer is widely used in laboratory experiments to demonstrate the pressure of air on a liquid column and vice versa. Manometer is classified as a simple manometer, U-tube manometer, Enlarged Leg Manom, and Well-type manometer inclined tube manometer.

## How to build a Manometer?

Let’s discuss how to build a U-tube manometer. A U-tube manometer is so-named because the primary component is a tube in the shape of a “U”. It’s included in school projects.

The plastic tube should be fastened to the board in the shape of a “U” using tube fasteners. The fasteners on the tube cannot prevent water from flowing freely through it. Make sure the tube’s “U” shape is smooth and devoid of any To provide a vertical reference, suspend a plumb bob.

Place the manometer so that the “U” shapes two valves are vertical and then firmly nail the plumb bob to the board 100 ml of water or so should be added to the beaker. Mix well after adding enough dye to turn the water a vibrant red color. Carefully pour the colored water into the tube.

Place a ruler vertically on one of the manometer’s sides. Position the ruler so that its zero point is level with the water’s surface inside the manometer. Without concealing the ruler’s scale, tape the ruler firmly in place.

To create a gas-tight seal, place one end of the manometer’s open ends over the nozzle of the gas source. To determine the pressure of the gas source about the atmospheric pressure in inches of water, measure the height of the water in the tube adjacent to the ruler.

## How does a manometer work?

A test pressure source is joined to the tube’s end via a gas-tight gasket. As the other end of the tube is exposed to the atmosphere, it will exert pressure of about 1 atmosphere. The liquid in the test column is driven down the column if the test pressure exceeds the reference pressure of 1 atmosphere. This results in an equal rise in fluid in the reference column.

## Calculate the pressure

The equation P=hgd can be used to calculate the pressure that a column of fluid is exerting. P is the computed pressure,h is the height of the fluid,g is the force of gravity and d is the density of the liquid in this equation. We substitute PI=Pa-Po because the manometer measures a pressure differential rather than an absolute pressure. Pa is the test pressure and PO is the reference pressure in this substitution.