FBI agents entered Thermotron Industries, 291 Kollen Park Drive, in the morning and instructed employees to remain in the cafeteria while they combed through the building. Employees were not allowed to use their work phones and could not leave the building until early afternoon.
The company makes pressure chambers used to test devices, some of which are sold in foreign countries. A source said the raid was in connection with a concern over national security.
As of 3 p.m. Wednesday, federal investigators remained at the company's offices.