def _get_columns_units(ifile, delimiter=','):
    """
    Extract units from third line of EddyPro output file `ifile`.
    """
    # read third line
    with open(ifile, "r", encoding='utf8') as f_id:
        f_id.readline()
        f_id.readline()
        header = f_id.readline().strip()
    # list of units
    col_units = header.split(delimiter)
    # remove brackets from unites and make empty units
    col_units = [ uu.replace('[', '').replace(']', '').replace('--', '')
                  for uu in col_units ]

    return col_units