For the most accurate results possible, the instrument should be calibrated before making any measurements. Refer to Calibration. If you want to perform a quick measurement without going through manual calibration, you may turn off User Cal and the instrument will apply the factory default calibration automatically (except for Transmission measurements).

OSL calibration components are used with Cable and Antenna Analyzer measurements and are available from Anritsu as optional accessories. For Transmission measurements, an external USB power sensor is used in the calibration setup and is connected to the S331P with a through test port cable or adapter.

The S331P Technical Data Sheet (part 11410-00964) contains a list of supported calibration components, adapters, and power sensors.