It’s easy for some people to get pressure confused with force, and vice-versa. One of the main reasons is because pressure cannot exist without force. While they are similar in this regard, the difference between the 2 is simple: force is the total impact of one object on another, whereas pressure is the physical quantity of force spread over a certain area.
What Is Force?
Force is defined as a push or a pull that causes an object to change its state of motion or direction. For example, when a ball is hit a force is applied on the ball: the ball, which was static, goes into a state of motion and remains in motion until it is stopped by friction and force of gravity. A force can either cause a moving body to stop, make it move faster, or change its direction.
Force is a vector quantity which means it has a magnitude as well as direction. Force is dependent upon the mass of the body which accelerates upon application of force and the three are related as per following equation: (Newton’s second law of motion)
Force= Mass x Acceleration
What is Pressure?
Pressure is the physical quantity of force spread over a certain area. In other words, pressure is force per unit area. If you take the amount of force being applied on a body, divide it with the area of contact, you will arrive at the pressure being applied on the body.
Pressure = force/area
This means that same force, when applied on a smaller area will produce greater pressure than when applied to a larger surface area. For example, the force I exert on the floor when standing on both feet is the same as the force I exert on the floor even while standing on one foot. However, when standing on one foot I put twice the pressure on the floor.
Force Vs. Pressure Sensor: Which Do I Need?
Force and pressure sensors are engineered with the same high technology, thin film strain gauge design. Available in similar materials as well, the main difference in the sensors is what the sensor is measuring and how it is doing so. For example pressure sensors are used inside tubing to measure any blockage or pinches in the line, taking the area into consideration to detect and measure the pressure in the tube. Force sensors are used in applications like dosing weighing systems, applications where load cells are placed under a flat surface where materials like granules, fibers, flakes, powders, or liquids are being continuously weighed.