C&T RF Antennas Inc provides information about pressure sensor basics. First, pressure sensors measure the pressure of fluids and gases using units like Pa, KPa, MPa, bar, and Kg/cm2. Each sensor has a measurement range. Second, sensor output signals are generally in mV and have a direct relationship with supply voltage. Third, common output signals include 4-20mA, 0-20mA, 0-5V, and RS485. Fourth, sensors connect to pipes or containers via threads or flanges. Fifth, the measurement range, output signal, and connection type must be clear before purchasing a sensor.