The function of a basic resistive pressure sensor is to measure pressure by utilizing the changes in electrical resistance of a resistive element when subjected to pressure or force. These sensors are also known as resistive pressure transducers or strain gauge pressure sensors.
The basic construction of a resistive pressure sensor typically consists of a thin diaphragm or sensing element made from a resistive material, such as a strain gauge. When pressure is applied to the diaphragm, it deforms slightly, causing a change in its dimensions and, consequently, a change in the resistance of the material.
Here's how it works:
Pressure application: The sensor is exposed to the pressure that needs to be measured. This could be the pressure of a gas or liquid.
Diaphragm deformation: The pressure causes the diaphragm to flex or deform. The extent of deformation is proportional to the applied pressure.
Resistance change: The resistive material, usually a strain gauge, is bonded to the diaphragm. As the diaphragm deforms, the dimensions of the strain gauge change, leading to a corresponding change in its electrical resistance.
Electrical output: The change in resistance results in a change in the electrical signal output from the strain gauge. This signal is typically in the form of a voltage or current.
Pressure measurement: The output signal can then be calibrated and converted into pressure units, allowing us to determine the pressure applied to the sensor.
It's worth noting that resistive pressure sensors are relatively simple and cost-effective compared to other types of pressure sensors, making them suitable for many industrial, automotive, and consumer applications. However, they might have limitations in terms of accuracy, temperature sensitivity, and long-term stability compared to more advanced pressure sensing technologies like piezoelectric or capacitive pressure sensors.