Miniature Pressure Sensors
Miniature pressure sensors are designed to unobtrusively measure the pressure of gases or liquids and then display the results in an understandable way. These sensors are very small and are designed for use in critical medical or biological applications, where the sensing instruments should provide a very low intrusion volume.
Miniature pressure sensors are composed of transducers, which are similar devices. Transducers convert one kind of energy into another kind; sensors, however, convert energy specifically to provide a readable measurement. Pressure sensors are classified according to the range of pressure they measure, the operating temperature range and the type of pressure they evaluate. There are five main categories of pressure sensors: absolute, differential, gauge, vacuum and sealed pressure sensors.
Practically any of these can be miniaturized. A typical pressure sensor is about a cubic inch in size, but miniature sensors can be a fraction of that size. They are usually comprised of at least two wires or probes attached to a round sensor. Usually ceramic, copper or metal components are used. Miniature pressure sensors are capable of accurately monitoring the pressure of fluid and can provide a cheaper alternative to flow sensors. They are used in weather instruments, aircraft and automobiles and can also monitor the engines in many different kinds of machinery.
Pressure sensors use a variety of techniques to take measurements. In general, however, pressure sensors turn the physical force being exerted on them into a reading that can be represented by a gauge, dial or display. Air and atmospheric pressure sensors use a silicon diaphragm that bends depending on how much force is exerted on it. A charge running through it communicates to the sensor the corresponding pressure and the sensor displays it.
Advancements in technology and materials have enabled sensors to become smaller and more accurate. Integrated circuits in particular make miniature pressure sensors possible because they can be very small while still retaining all the necessary components. Pressure sensors can benefit from the use of calibrators and regulators. Pressure calibrators are devices that measure the pressure and then compare that to what the pressure sensor reads.
They help maintain accuracy, which is important for many pressure systems. Sensors are able to detect and report pressures with a margin of error less than one percent. Pressure regulators monitor and control the actual flow of pressure and are often found directly on a nozzle or valve. As a safety and loss management precaution, regulators and sensors can be programmed to alert operators if the system’s pressure is too high or too low.