Measurand ShapeArrays (SAAs) do not need to be re-calibrated. The sensors used in their construction do not drift. All current model ShapeArrays are resistant to twist and do not require re-calibration.
Measurand’s SAAScan should be used for applications that require the ShapeArray to be used repeatedly for measurements in a large number of boreholes. There is no specification for re-calibration frequency for the SAAScan it has been designed and tested to withstand millions of usage cycles. Re-calibrations can only be completed at Measurand's facility and are typically only performed if you suspect the instrument is damaged and requires repairs, or if a job site requires an updated calibration certificate for the instrument.