In any county of this State the county superintendent of weights and measures and the assistant county superintendents of weights and measures, where such persons have served for a continuous period of twenty years, and have reached the age of sixty years, shall, upon their respective applications, in writing, be retired upon one-half pay. The words "be retired upon one-half pay," as used in this act, shall be construed to mean retirement upon a pension equal to one-half of the annual salary of such person at the time of retirement.
N.J.S. § 43:10-106