def _get_default_range(mdvfile, field):
    """ Return the default range for a field. """
    def_ranges = {
        'DBMHC': [-100, 0],
        'DBMVC': [-100, 0],
        'DBZ': [-16.0, 64.0],
        'DBZ_F': [-16.0, 64.0],
        'DBZVC': [-16.0, 64.0],
        'DBZVC_F': [-16.0, 64.0],
        'VEL': [-1.0*mdvfile.radar_info['unambig_vel_mps'],
                mdvfile.radar_info['unambig_vel_mps']],
        'VEL_F': [-1.0*mdvfile.radar_info['unambig_vel_mps'],
                  mdvfile.radar_info['unambig_vel_mps']],
        'WIDTH': [0.0, 10.0],
        'WIDTH_F': [0.0, 10.0],
        'ZDR': [-3, 6.0],
        'ZDR_F': [-3, 6.0],
        'RHOHV': [0.6, 1.0],
        'RHOHV_F': [0.6, 1.0],
        'PHIDP': [0, 180.0],
        'PHIDP_F': [-180.0, 180.0],
        'KDP': [-2, 6],
        'KDP_F': [-2, 6],
        'NCP': [0, 1],
        'NCP_F': [0, 1]}
    return def_ranges[field]