The Agilent/Keysight Technologies N1923A Wideband Power Sensor, 50 MHz to 18 GHz, -35 to +20 dBm, Refurbished provides internal zero and calibration by integrating a DC reference source and switching circuits into the power sensor. This feature eliminates the multiple connections associated with using an external calibration source, thus minimizing connector wear, test-time and measurement uncertainty.