U.S. Nuclear Corp. has started delivery this month of its portable tritium air monitors to the U.S. Air Force. The $772,500 contract has the Canoga Park company delivering 10 of the monitors by the end of October, and continuing at 15 monitors a month until the quota of 100 units is reached next year. Chief Executive Robert Goldstein said the order represents a sizeable quantity for the small, publicly traded company. “We successfully allocated our production schedule so that we can steadily produce 15 units to be shipped every month, while simultaneously completing all other current jobs on the backlog,” Goldstein said in a prepared statement. U.S. Nuclear subsidiary Overhoff Technologies in Milford, Ohio, is one of less than a handful of companies producing detectors that can spot tritium, the weakest radiation emitter which in turn makes it difficult to detect and measure. Shares in U.S. Nuclear (UCLE) closed up Monday 1 cent, or 4 percent, to 26 cents on the over-the-counter market.