225 ILCS 705/32.02

The person authorized to weigh the coal and keep the record thereof shall be a citizen of the United States or lawfully admitted for permanent residence, and shall, before entering upon his duties, make and subscribe to an oath before some person duly authorized to administer oaths, that he will accurately weigh and carefully keep a true record of all coal weighed, and such affidavit shall be kept conspicuously posted at the place of weighing.