@staticmethod
def get_raw_units():
    """Include the settings for the units used by the instrument.

        The units are defined w.r.t. the SI units ('unit-fractions'; currently only units that are multiples of
        Si units can be used). For example, for current defined in mA, the value for the
        current unit-fraction will be 0.001.

        Returns: dictionary containing the unit-fractions for current, charge, and mass

        """
    raw_units = dict()
    raw_units['voltage'] = 1.0
    raw_units['current'] = 1.0
    raw_units['charge'] = 1.0
    raw_units['mass'] = 0.001
    raw_units['energy'] = 1.0
    return raw_units
