Pressure transducer, differential pressure sensor, what is the difference between negative pressure sensor?

Able to measure the pressure sensor can collectively called pressure sensor. Generally speaking, what we call the pressure sensor, is not measuring pressure difference, but only the size of measuring the pressure of a pressure sensor. In diaphragm sensor, you can refer to below: pressure sensor, end points, one end of the atmospheric or vacuum pressure seal, it can only measure one relative to atmospheric pressure, and relative to the vacuum pressure, and can't measure the pressure difference between the two different pressure. Differential pressure sensor is to open the general atmosphere end of the pressure sensor ( Sealing side) So that it can measure the pressure difference between the two different pressure. If the differential pressure sensor at one end of the atmosphere, you can use it as a pressure sensor, pressure measurement. Negative pressure sensor is a kind of pressure sensor, one end is measurement point, atmospheric pressure, Differential pressure) Sensor, but negative pressure sensor measured pressure is smaller than atmospheric pressure, pressure on diaphragm is not 'pressure', but 'absorption. The diagram below: