Depending on your industry and need, there is probably a pressure sensor designed exactly for what you are looking to do. By some estimates, there are more than 50 different types of pressure transducer technologies, each designed for different, specialized tasks. Typically, pressure sensors can be divided into five categories based on the type of pressure they measure:
Absolute pressure sensor: measures pressure relative to a perfect vacuum pressure of 0 PSI (air pressure at sea level is around 14.7 PSI).
Gauge pressure sensor: a pressure transmitter that measures the pressure relative to the atmospheric pressure. A tire air pressure gauge is one example.
Sealed pressure sensor: similar to a gauge pressure sensor, except that it is manufactured to read the pressure relative to a set air pressure (regardless of the outside air pressure).
Vacuum pressure sensor: designed to measure pressures that are less than the external atmospheric pressure.
Differential pressure sensor: measures differences in pressures in two units, or the flow of pressure across different areas. Many custom pressure transducer items are created to measure differential pressures.