Hello Gustavo,
The MPX2300DT is a unidirectional sensor, which means that it can only sense pressure in one direction. All of our pressure sensors are designed for P1>P2, however, depending on the application, you could use pressure port P2 to measure vacuum, this way you keep the P1>P2 condition.
Unfortunately the MPX2300DT has only one available port (P1), however the pressure port P2 is the front side of the sensor (where you can see the die and wirebonds), if you could manufacture a custom connector to apply pressure to the front of the sensor, you could measure vacuum with it, see attached image for an example of a custom connector.
Another option would be to choose a different pressure sensor with two pressure ports and simply apply vacuum to port 2.
Hope it helps.
Josh
