выдерживать на воздухе.
• These surfaces have been allowed to stand in air [or have been kept (or held) in air] for half an hour after polishing.
Источник:
Русско-английский научно-технический словарь
на Gufo.me
• These surfaces have been allowed to stand in air [or have been kept (or held) in air] for half an hour after polishing.