EXHIBIT 10.3

                                 THIRD AMENDMENT
                            DATED AS OF JUNE 28, 2002
                                       TO
                         RECEIVABLES PURCHASE AGREEMENT
                           DATED AS OF OCTOBER 1, 1999

      THIS THIRD AMENDMENT (the "Amendment"), dated as of June 28, 2002 is
entered into among Ametek, Inc. ("Ametek"), Rotron Incorporated ("Rotron")
(each of Ametek and Rotron being referred to individually, as an "Originator"
and collectively, as the "Originators"), Ametek Receivables Corp. (the
"Company") and Advanced Measurement Technology, Inc. ("Advanced"), Patriot
Sensors and Controls Corporation ("Patriot") and EDAX Inc. ("EDAX").


                                   WITNESSETH:

      WHEREAS, the Originators and the Company have heretofore executed and
delivered a Receivables Purchase Agreement, dated as of October 1, 1999 (as
amended, supplemented or otherwise modified through the date hereof, the
"Purchase Agreement"), and

      WHEREAS, the parties hereto desire to add Advanced, Patriot and EDAX as
Originators under the Purchase Agreement effective as of June 28, 2002 (the
"Effective Date").

      NOW, THEREFORE, for good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, the parties hereto hereby agree that
the Purchase Agreement shall be and is hereby amended as follows:

      Section 1. (a) From and after the Effective Date, the defined term
"Originator" shall be amended to include Advanced, Patriot and EDAX
(collectively, the "New Originators"). In addition, from and after the Effective
Date Advanced, Patriot and EDAX agree to be bound by all of the terms and
conditions applicable to an Originator contained in the Purchase Agreement and
other Transaction Documents. Subject to the terms and conditions of the Purchase
Agreement, each New Originator hereby sells to the Company, and the Company
hereby acquires from such New Originator, all of such New Originator's right,
title and interest in the Purchased Receivables of such New Originator, the
Related Security and related Collections. Each New Originator intends such sale
to be a true sale of all rights and interest of such New Originator in the
Receivables of such New Originator in existence on the Initial Purchase Date and
of each Receivable thereafter generated by such New Originator as it is created
until the Originator Termination Date for such New Originator.

      (b) In connection with the execution of this Amendment, Advanced, Patriot
and EDAX agree to deliver each of the documents set forth in Section 7.1 of the
Receivables Sale Agreement, to the extent that such documents are applicable.

      Section 2. This Amendment shall become effective on the date the Agent has
received counterparts hereof executed by each Originator and the Company.

      Section 3. This Amendment may be executed in any number of counterparts
and by the different parties on separate counterparts and each such counterpart
shall be deemed to be an original, but all such counterparts shall together
constitute but one and the same Amendment.

      Section 4. Except as specifically provided above, the Purchase Agreement
and the other Transaction Documents shall remain in full force and effect and
are hereby ratified and confirmed in all respects. All defined terms used herein
and not defined herein shall have the same meaning herein as in the Transaction
Documents. The Company agrees to pay on demand all costs and expenses (including
reasonable fees and expenses of counsel) of or incurred by the Agent and the
Originators in connection with the negotiation, preparation, execution and
delivery of this Amendment.

      Section 5. This Amendment and the rights and obligations of the parties
hereunder shall be construed in accordance with and be governed by the law of
the State of New York.









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      IN WITNESS WHEREOF, the parties have caused this Amendment to be executed
and delivered by their duly authorized officers as of the date first above
written.


                                       AMETEK, INC.


                                       By: Deirdre D. Saunders
                                          -----------------------
                                       Title: VP & Treasurer


                                       ROTRON INCORPORATED


                                       By: Deirdre D. Saunders
                                          -----------------------
                                       Title: Treasurer


                                       ADVANCED MEASUREMENT TECHNOLOGY, INC


                                       By: Deirdre D. Saunders
                                          -----------------------
                                       Title: Treasurer


                                       PATRIOT SENSORS AND CONTROLS CORPORATION


                                       By: Deirdre D. Saunders
                                          -----------------------
                                       Title: Treasurer


                                       EDAX INC.


                                       By: Elvin J. Stoltzfus
                                          -----------------------
                                       Title: Treasurer


                                       AMETEK RECEIVABLES CORP.


                                       By: Deirdre D. Saunders
                                          -----------------------
                                       Title: Treasurer



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