The DPT700 is a low differential pressure sensor, available from Ptronik formerly P Thomas Electronics , suitable for air or electrically non-conducting gases. The sensor is true two-wire device and delivers a 4mA to 20mA output signal proportional to differential pressure. The unit is calibrated at the factory using 250 ohm load at 24V DC and should require no field adjustment. However, the offset and gain adjustments are accessible.
The zero may be adjusted with pressure ports open to atmosphere while monitoring the current output. Users should adjust the offset potentiometer until the reading is 4mA. This adjustment should only be performed by using an accurate pressure standard. With full scale pressure (400mm H2O) applied to the high pressure port and low pressure port open to atmosphere, users should adjust the gain potentiometer to 20mA.