A transducer is also known as a sensor. Pressure sensors are used to measure the pressure of liquids and gasses. Pressure is actually the force that is exerted on a liquid to stop it from expanding. It is stated as force per unit area. When a pressure sensor is put in place, it emits a signal depending on the pressure imposed upon it.
Varieties of Pressure Sensors
There are many different sensors out there for pressure measurement. They vary in design, cost, technology, application suitability and performance. If you are looking to have a sensor that measures in a mode that is dynamic, there is a category for that too. It measures high-speed pressure changes such as would be experienced in gas turbines. The materials that such sensors would be made of are piezoelectric like quartz.
Classifications of Pressure Measurements
In order to classify pressure transducers, you need to consider measurement ranges, the temperature range under which the sensor can operate and the kind of pressure it measures. Many times though, the naming of these sensors will tell you their purpose. Here are just a few types of pressure sensors:
- Absolute – This one measures pressure in relation to a perfect vacuum. A barometer is a good example.
- Gauge – This one measures pressure in relation to atmospheric pressure. A good example of this is the pressure gauge you use for your tires.
- Vacuum – This one measures pressure that is below atmospheric pressure. It indicates negative gauge pressure that is the difference between atmospheric pressure and the low pressure. It is also used to describe a measure of pressure that is low in relation to a perfect vacuum.
- Differential – This is a sensor that takes into account two pressure readings and gives the difference. These are used in diverse ways to give information on pressure drops, fluid levels, and flow rates.
- Sealed – This one works just like the gauge sensor but instead of giving a measurement in relation to atmospheric pressure which changes based on weather and location, there is a fixed pressure point given.
Applications of Pressure Sensors
Pressure sensors can be used in a variety of applications. Here are just a few:
- Sensing pressure – they are used to measure pressure in weather instrumentation, automobiles, machinery and aircrafts.
- Sensing Altitude – pressure sensors are used in weather balloons, rockets, aircraft and satellites as well as other applications. They measure the pressure in relation to altitude.
- Flow measurements – Working with the venture effect, pressure sensors can measure flow. A venture tube is used and measurements taken from two different segments. The differential is then given as the pressure reading. Usually the difference in pressure between the two segments is low so the sensor is usually a low pressure one.
- Level sensing – usually this is employed to measure how deep a submerged body is, for example a submarine or a diver.
- Testing a leak – If there is a system leak, there will be a decay of pressure that can be detected using a pressure sensor.