Differential Pressure Transmitter

Pressure is experienced when a force is applied on an area. This means that we can increase the pressure by either increasing the force or by reducing the area. We also tend to think of force in terms of weight (this is only true, if gravity is constant). As an example, the force produced by 1lb of weight due to gravity acting on 1 inch x 1 inch (1sq inch) would produce a pressure of 1lb/sq inch, this is often written as 1 Psi (1 pound per square inch). If the same 1lb was applying a force to only half the area, we would actually say the pressure was equal to 2 Psi. In our day to day experience we may pump our car tyres to 26 Psi.

We also experience pressure in the form of weather (or atmospheric pressure). This could be considered the force being appleid by the atmosphere on our heads. As the atmospheric pressure changes, so does the weather. High pressure  usually referes to clear sunny days, while low pressure produces cloudy ones.