A Rigol RSA5000-AMK Advanced Measurement Kit licence permanently enables the following advanced measurement functions on Rigol RSA5000 series real-time spectrum analysers: T-Power (Time domain Power), ACP (Adjacent Channel Power), Chan Pwr (Channel Power), OBW (Occupied Bandwidth), EBW (Emission Bandwidth), C/N Ratio, Harmo Dist (Harmonic Distortion) and TOI (Third-Order Intermodulation). The advanced measurement functions are accessed via the 'Meas' button on the front panel. Press 'Meas Fctn' to access the advanced measurement functions. The screen will be divided into two windows: The upper window will display the sweep trace and the lower window will display the measurement results. Each licence contains a unique product key. The product key is used to generate a software licence code that must be entered into your instrument. To generate a Rigol software licence code using your Rigol product key, please see HERE. Installed software licence codes are permanent - They are unaffected by Rigol firmware updates.