• The airflow measured at ground level is due to ...
• There is a chain-operated conveyor at ground level .
• The airflow measured at ground level is due to ...
• There is a chain-operated conveyor at ground level .
Циммерман М., Веденеева К.. Русско-Английский научно-технический словарь переводчика. Russian-English scientific dictionary for translators. 2012