The 1136 Differential Pressure Sensor is a dual ported air pressure sensor that measures the pressure difference between the two ports. It can measure both positive and negative pressure from –2 kPa to +2 kPa. This sensor is designed to measure the pressure of clean, non-condensing air. Contact with moist air (i.e, human breath), dusty air, or other gases can shorten the lifespan of the sensor.