code: def isValid(self):
          
          return self.isOutOfDate() is False \
              and self.isQCValid() is True \
              and self.getDisposeUntilNextCalibrationTest() is False \
              and self.isValidationInProgress() is False \
              and self.isCalibrationInProgress() is False
docs: Returns if the current instrument is not out for verification, calibration,
          out-of-date regards to its certificates and if the latest QC succeed