Measuring pressure is necessary in the control of most industrial processes.

A pressure sensor converts pressure information into an electrical signal. Most pressure sensors measure the deformation of a membrane under the effect of the difference in the pressure applied to both sides. Manufacturers use different terms for these products. While “pressure sensor” and “pressure transducer” can be considered synonyms, the term “pressure transmitter” refers to a pressure sensor equipped with measurement electronics allowing it to deliver a standardized output signal.

Once you have determined whether you need to measure absolute, relative or differential pressure and have chosen a type of sensor technology, you still have to choose the right model based on the following criteria:

• First of all, it is important to choose a sensor with a measuring range that corresponds with the pressure range you need to measure, taking into account normal conditions and possible occasional pressure variations.
• The operating temperature is also important. Most sensors have an operating range between -25°C and 100°C. Beyond this, it is necessary to use sensors designed to withstand higher temperatures.
• As with any sensor, you must choose a pressure sensor with an output signal that corresponds with your measurement or control loop.
• The last important selection criterion is the configuration of the sensor and how it is mounted to the point of measurement. Most sensors are threaded, allowing for easy mounting on a nozzle installed on a pipe, tank, etc. There are also sensors equipped with flanges, miniature sensors to be soldered on a circuit board, etc. The installation of flush diaphragm sensors also has its advantages. In this configuration, the sensor membrane is flush with the pipe wall, avoiding clogging problems due to material accumulation in areas without flow. This configuration is very useful for liquids containing solid elements, especially in the food industry.