Pounds per square inch is normally abbreviated as psi. It represents the amount of force measured particularly in pounds when exerted on one square inch area. Basically, it is one of the units of pressure. It is not its SI (System International) unit. SI units of physical quantities are used in the whole world for industrial and commercial uses. But psi unit is for technical and local pressure measurement uses, such as for measuring the pressure of tires.
What are Pressure and PSI:
We come across the word pressure a lot in our daily life. So we have to understand completely that, what is pressure, how and in which units it is measured. So the pressure is defined as the force applied to a particular area. We use the words, force, and pressure interchangeably in our daily life, but science makes a distinction between them. They are different physical quantities that are measured in different units. The SI unit of pressure is Pascal. While the SI unit of force is Newton. For example, when we apply a force of one newton on one meter square area, then the pressure would be of one pascal. The value of pressure would be obtained by dividing the value of force by the value of the area on which force is exerted.
Psi is also a very common unit of pressure. It is not an SI unit of pressure rather it is the imperial system unit of pressure. It stands for pounds per square inch. When the measurement of pressure for gases and liquids is concerned then the psi unit is commonly preferred for pressure.
PSI Pressure in our daily life:
We use pressure in our daily life for different purposes. To give an idea, a few examples are discussed here.
We mostly cook our meal or food in pressure cookers. These cookers make use of air pressure and water vapor pressure to cook the food effectively and efficiently. If we want to measure this pressure, this would also be measured in psi because we are dealing with gases i.e. air and water vapors.
When the air pressure of our bikes, bicycles, or cars gets low, then we go to tire shops to refill the lost air of tires. There, the tires are filled with air and the pressure is measured and checked in a psi unit with a gauge.
We use vacuum cleaners and pressure washer pumps in our homes for different types of cleaning. Vacuum cleaners use air whereas pressure washer pumps use water to clean up things. So their pressure is also adjusted to the right amount of psi.
Conversion of psi to pascal:
The units of physical quantities are normally convertible. One unit of a physical quantity like pressure, force, time, speed, etc can be converted to units of other systems. For example, the units of the metric system can be converted to the MKS system and vice versa. The same is the case with SI units. Therefore psi unit can also be converted to pascals. Their relation is given below:
1 psi = 6895 pascal
1 pascal = 0.000145 psi