Every person (including every firm or corporation) within any of the classes specified in 320.1 of this Part shall upon the presentation of official credentials by any department employee or other duly authorized representative of the commissioner, during ordinary business hours, permit such representative to enter his or its place of business and examine the records required to be kept by section 320.1 and the facilities and inventory pertaining to the business of such person subject to the law, and to copy all such records, and to take reasonable samples of the inventory. Any necessary facilities (other than reproduction equipment) for such examination and copying of records and for such examination and sampling of inventory shall be afforded to such department employee or other authorized representative of the commissioner.