def _create_xy_header(self):
        """
        Creates the header for the xy file format (contains information about calibration parameters).
        :return: header string
        """
        header = self.calibration_model.create_file_header()
        header = header.replace('\r\n', '\n')
        header = header + '\n#\n# ' + self._integration_unit + '\t I'
        return header