This sensor measures pressures produced by LEGO Pneumatics systems and lot more!
The pressure range of this sensor is from 0 to 58 PSI.
The sensor measures absolute pressure as well as relative pressure. (You can set reference pressure, and measure change in pressure relative to that reference).
This is a I2C sensor (Digital), and compatible with NXT-G, RobotC, BricxCC/NXC.
The sensor also features Data Logging in NXT-G Educational version.