EG&G Inc. based in Wellesley, Mass., announced that it changed its name to PerkinElmer Inc., effective Oct. 26. The change reflects a focus on commercial markets and a move to develop under a recognized brand, the company said. EG&G acquired the analytical instruments division of Norwalk, Conn.-based Perkin-Elmer Corp. earlier this year. EG&G's third-quarter instrument sales grew 280 percent to $200.5 million as a result of growth in its security business and the acquisition of the Perkin-Elmer division, which posted 1998 sales of $569 million.