The members of any other advisory committees appointed pursuant to this chapter who are not officers or employees of the United States while attending conferences or meetings or while otherwise serving at the request of the Administrator, shall be entitled to receive compensation at a rate to be fixed by the Administrator, but not exceeding $100 per diem, including traveltime, and while away from their homes or regular places of business they may be allowed travel expenses, including per diem in lieu of subsistence, as authorized by section
5703 of title
5 for persons in the Government service employed intermittently.