def get_instrument_list(filtdcat):
    """ Retrieve clean instrument list without any codes """
    return filtdcat[['array_name', 'site_name', 'infrastructure_name',
        'instrument_name', 'stream_method', 'stream_rd']].sort_values(by=[
        'site_name', 'infrastructure_name', 'instrument_name']
        ).drop_duplicates().reset_index(drop='index')
