In addition to the territorial standards provided for in the preceding section of the subchapter, there shall be at least one complete set of copies of these standards to be kept in the office or laboratory of the Consumer Services Administration to be known as office standards, and also such field standards and such equipment as may be found necessary to carry out the provisions of this subchapter. The office standards shall be verified upon their initial receipt and at least once each year thereafter. The field standards shall be verified upon their initial receipt and at least once every five years thereafter, the office standards by direct comparison with the territorial standards and the field standards by direct comparison with the office standards.