> Calibration and Annual Verification
> The Cable and Antenna Analyzer requires user performed calibration before making line sweep measurements. Calibration can be quickly and easily performed at the end of a test port cable (not included) using the built-in InstaCal module. External OPEN, SHORT, and LOAD (OSL) calibration method is another option and requires Anritsu OSL components which are sold separately. Flex Cal is supported using either calibration method. Refer to Calibration for additional information.
> The external InstaCal Calibration Modules (ICN50 and ICN50B) are NOT compatible with the Site Master S331L.

> Note | Anritsu recommends allowing the S331L to warm up for 5 minutes to typical operation temperature before calibrating. The instrument will require a new calibration if the internal instrument temperature changes more than ±20 ºC after calibration.

> Anritsu recommends an annual calibration and performance verification of the Site Master by local Anritsu service centers. Anritsu service also recommends a semi-annual verification of OSL calibration components.
> The Site Master is self-calibrating and there are no field-adjustable components. The OSL calibration components and the Internal InstaCal are crucial to the integrity of the user calibration. As a result, they must be verified periodically to ensure performance conformity. This is especially important if the OSL calibration components have been accidentally dropped or over-torqued.