Measurement of Pressure

MEASUREMENT OF PRESSURE

The pressure of a fluid is measured by using the following two principles.

1. Principle of Balancing a Liquid Column

The pressure of a fluid is measured at a point in a fluid by balancing the column of same liquid or the column of another liquid. According to this principle, the instruments used to measure the pressure of a liquid are called manometers.

Manometers are classified as

(i) Simple manometers

(ii) Differential manometers

2. Principle of Supporting a Dead Weight or a Spring Force

The pressure of a fluid is measured at a point in a fluid by balancing the force of a spring or dead weight. According to the principle, the instruments used to measure the pressure of a fluid are called mechanical gauges.

Mechanical gauge are classified as,

(i) Diaphragm pressure gauge

(ii) Bourdon tube pressure gauge

(iii) Dead-weight pressure gauge

(iv) Bellows pressure gauge