EXHIBIT 3.49

                            ARTICLES OF INCORPORATION

                                       OF

                      PRESSURE SYSTEMS INTERNATIONAL, INC.

         We, the undersigned, hereby associate to form a stock corporation under
the provisions of Chapter 1 of Title 13.1 of the Code of Virginia, and to that
end set forth the following:

         1.       The name of the corporation is Pressure Systems International,
Inc.

         2.       The purposes for which the corporation is organized are as
follows:

                  (a)      To sell or lease as export goods, goods produced in
         the United States consisting of electronic instrumentation and other
         goods manufactured for industrial purposes including, but not limited
         to, pressure measuring and sensing devices and electronic computer
         based date acquisition systems.

                  (b)      Generally, to do each and every act or acts necessary
         to the conduct and operation of the business herein set forth; and to
         engage in any lawful business not prohibited to general corporation
         organized under the laws of the Commonwealth of Virginia.

         3.       The aggregate number of shares which the corporation shall
have authority to issue and the par value per share are as follows:



   CLASS        NUMBER OF SHARES    PAR VALUE PER SHARE
------------    ----------------    -------------------
                              
Common Stock         5,000                 $10.00


         4.       The post office address of the initial registered office is
12482-H Warwick Boulevard, Post Office Box 6621, Newport News, Virginia 23606.
The name of the City in which the initial registered office is located is
Newport News, Virginia. The name of the initial registered agent is Richard S.
Gordon, who is a member of the Virginia State Bar and a resident of the State of
Virginia and whose business office is the same as the registered office of the
corporation.



         5.       The number of directors constituting the initial Board of
Directors is three (3) and the names and addresses of the persons who are to
serve as the initial directors are:



         NAME                      ADDRESS
----------------------     -------------------------
                        
Douglas B. Juanarena       2534 College Boulevard
                           Newport News, VA. 23606

Chris Gross                500 Marlbank Drive
                           Yorktown, VA. 23690

Richard S. Gordon          688 Village Green Parkway
                           Newport News, VA. 23606


Dated: April 22, 1982.

                                                     /s/ RICHARD S. GORDON
                                                --------------------------------
                                                RICHARD S. GORDON, INCORPORATOR

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