GUARANTEE AGREEMENT


             Thermo Electron Corporation, a Delaware corporation ("Thermo
        Electron"), and ThermoLyte Corporation, a Delaware corporation
        ("TLT"), agree as follows:

             WHEREAS, TLT plans to issue and sell in a private placement
        up to 1,845,000 shares of Common Stock (the "TLT Common Stock")
        and 1,845,000 redemption rights providing the holder the right to
        require TLT to repurchase TLT Common Stock during certain annual
        exercise periods (the "Redemption Rights"); and

             WHEREAS, such sale of TLT Common Stock will be materially
        enhanced by the existence of a subordinated guarantee by Thermo
        Electron of the Redemption Rights.

             NOW, THEREFORE, Thermo Electron and TLT do hereby covenant
        and agree as follows:

             Article   1.   Thermo Electron agrees to guarantee as
        provided in the Guarantee dated the date hereof and attached
        hereto as Exhibit A, on a subordinated basis, the due and
        punctual payment of any amounts due from TLT to its holders of
        Common Stock pursuant to the Redemption Rights.  For purposes of
        this Agreement, all of the Guarantees of the Redemption Rights
        referred to in the preceding sentence shall be referred to as the
        "Guaranty."

             Article 2.     The text of the Guaranty shall be endorsed on
        the back of each Redemption Right certificate and shall be
        executed by duly authorized officer of Thermo Electron, which
        execution shall be attested.  Such signatures may be manual or
        facsimile.

             Article 3.     Upon the failure or prospective failure of
        TLT to meet its redemption obligations during any Annual
        Redemption Period, as that term is defined in the Redemption
        Rights, TLT shall deliver to Thermo Electron, a statement of the
        failure or prospective failure of TLT to meets its obligations
        and the correct amount to be paid in respect of such redemption.
        This statement shall be delivered at the earliest practicable
        time.  Failure of TLT to deliver such a statement shall not
        relieve Thermo Electron of its obligations under this Agreement
        or the Guaranty.

             Article 4.     This Agreement may be amended only by written
        amendment signed by both parties and no such amendment that is
        materially adverse to the rights of any holder of the Redemption
        Rights shall be effective against the holders of the Redemption
        Rights without the consent of a two-thirds in interest of such
        holders other than Thermo Electron, its subsidiaries, any other
        corporation owning a majority of the Common Stock of TLT or any
        other entity that is not a natural person and that is an
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        "affiliate" (as that term is defined in Rule 405 under the
        Securities Act of 1933) of Thermo Electron Corporation or such
        other entity.

             Article 5.     This Agreement is effective as of the 7th day
        of March, 1995 and shall terminate on the date that the
        redemption obligations of TLT under the Redemption Rights have
        been satisfied in full.

             Article 6.     This Agreement has been entered into by TLT
        and Thermo Electron for the benefit of the holders of the
        Redemption Rights and such holders are third party beneficiaries
        hereof.

             Executed as a sealed instrument.

                                        THERMOLYTE CORPORATION


                                        By:  Marshall J. Armstrong



                                        THERMO ELECTRON CORPORATION



                                        By: Jonathan W. Painter