Sampling checks were constantly conducted on Chogin to ascertain the percentage of silver in them by applying the process of cupellation after lead had been added to remove any impurities; those which did not meet the required quality standard were refined again.
銀座では常に鋳造された丁銀は灰吹法による糺吹（ただしふき）すなわち銀品位の抜き取り検査が行われ、規定の品位の基準を満たさないものは吹き戻され作り直された。