SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549
                   ------------------------------------------
                                    FORM 10-K
   (mark one)
   [ X ] Annual Report Pursuant to Section 13 or 15(d) of the Securities
         Exchange Act of 1934 for the fiscal year ended December 28, 1996

   [   ] Transition Report Pursuant to Section 13 or 15(d) of the Securities
         Exchange Act of 1934
                          Commission file number 1-9567

                                 THERMEDICS INC.
             (Exact name of Registrant as specified in its charter)

   Massachusetts                                                    04-2788806
   (State or other jurisdiction of                            (I.R.S. Employer
   incorporation or organization)                          Identification No.)

   470 Wildwood Street, P.O. Box 2999
   Woburn, Massachusetts                                            01888-1799
   (Address of principal executive offices)                         (Zip Code)

       Registrant's telephone number, including area code: (617) 622-1000

           Securities registered pursuant to Section 12(b) of the Act:
         Title of each class       Name of each exchange on which registered
     ----------------------------  -----------------------------------------
     Common Stock, $.10 par value           American Stock Exchange

          Securities registered pursuant to Section 12 (g) of the Act:
                                      None

   Indicate by check mark whether the Registrant (1) has filed all reports
   required to be filed by Section 13 or 15(d) of the Securities Exchange Act
   of 1934 during the preceding 12 months, and (2) has been subject to the
   filing requirements for at least the past 90 days. Yes [ X ] No [   ]

   Indicate by check mark if disclosure of delinquent filers pursuant to Item
   405 of Regulation S-K is not contained herein, and will not be contained,
   to the best of the Registrant's knowledge, in definitive proxy or
   information statements incorporated by reference into Part III of this Form
   10-K or any amendment to this Form 10-K. [   ]

   The aggregate market value of the voting stock held by nonaffiliates of the
   Registrant as of January 24, 1997, was approximately $295,395,000.

   As of January 24, 1997, the Registrant had 36,677,656 shares of common
   stock outstanding.

                       DOCUMENTS INCORPORATED BY REFERENCE

   Portions of the Registrant's 1996 Annual Report to Shareholders for the
   year ended December 28, 1996, are incorporated by reference into Parts I
   and II.

   Portions of the Registrant's definitive Proxy Statement for the Annual
   Meeting of Shareholders to be held on June 2, 1997, are incorporated by
   reference into Part III.
PAGE
<PAGE>
                                     PART I

    Item 1. Business

    (a)  General Development of Business

        The businesses of Thermedics Inc. (the Company or the Registrant) are
    divided into two segments: Instruments and Other Equipment, and
    Biomedical Products. The Company's Instruments and Other Equipment
    segment includes Thermo Sentron Inc. (Thermo Sentron), which designs,
    develops, manufactures, and sells high-speed precision-weighing and
    inspection equipment for industrial production and packaging lines. On
    January 2, 1996, the Company transferred to Thermo Sentron the assets,
    liabilities, and business of Ramsey Technology, Inc., acquired in March
    1994, for 7,000,000 shares of Thermo Sentron common stock. In April 1996,
    Thermo Sentron completed the sale of shares of common stock in its
    initial public offering for net proceeds of approximately $42.3 million.
    Also part of the Instruments and Other Equipment segment is the Company's
    Orion laboratory products division (Orion), acquired in December 1995.
    Orion is a manufacturer of electrode-based chemical measurement and other
    instruments used to analyze the composition of foods, beverages,
    pharmaceuticals, and other products and detect contaminants in
    high-purity water. Through the Company's Thermedics Detection Inc.
    (Thermedics Detection) subsidiary, the Instruments and Other Equipment
    segment also develops, manufactures, and markets high-speed, on-line
    detection instruments used in a variety of industrial process
    applications, explosives detection, and laboratory analysis. In January
    1996, Thermedics Detection acquired the assets and certain liabilities of
    Moisture Systems Corporation and certain affiliated companies
    (collectively, Moisture Systems) and the stock of Rutter & Co. B.V.
    (Rutter) for a total of $21.7 million in cash, which included the
    repayment of $0.7 million of debt. Moisture Systems and Rutter design,
    manufacture, and sell instruments that use near-infrared spectroscopy to
    measure moisture and other product components. In March and November
    1996, Thermedics Detection issued shares of its common stock in private
    placements for net proceeds of $7.0 million. In February 1997, a
    registration statement, under the Securities Act of 1933, covering shares
    of common stock to be sold in Thermedics Detection's initial public
    offering was declared effective by the Securities and Exchange
    Commission. The Instruments and Other Equipment segment, through the
    Company's Thermo Voltek Corp. (Thermo Voltek) subsidiary, also
    manufactures a line of electromagnetic compatibility testing instruments,
    high-voltage power conversion systems, and programmable power amplifiers.

        As part of its Biomedical Products segment, the Company's Thermo
    Cardiosystems Inc. (Thermo Cardiosystems) subsidiary has developed two
    implantable left ventricular-assist systems (LVAS): a pneumatic, or
    air-driven, system and an electric version. The Company also develops,
    manufactures, and markets enteral nutrition-delivery systems and a line
    of medical-grade polymers used in medical disposables and nonmedical,
    industrial applications, including safety glass and automotive coatings.

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        The Company was incorporated in 1983 under the laws of Massachusetts
    as a wholly owned subsidiary of Thermo Electron Corporation (Thermo
    Electron). Prior to that time, the business of the Company was conducted
    by the R & D/New Business Center of Thermo Electron. As of December 28,
    1996, Thermo Electron owned 20,293,310 shares of the Company's common
    stock, representing 55% of such stock outstanding. Thermo Electron is a
    world leader in environmental monitoring and analysis instruments,
    biomedical products such as heart-assist devices and mammography systems,
    papermaking and recycling equipment, biomass electric power generation,
    and other specialized products and technologies. Thermo Electron also
    provides a range of services related to environmental quality.

        Thermo Electron intends, for the foreseeable future, to maintain at
    least 50% ownership of the Company. This may require Thermo Electron to
    purchase additional shares of the Company's common stock (or debentures
    convertible into common stock) from time to time, as the number of the
    Company's outstanding shares increases. These or any other purchases may
    be made either in the open market or directly from the Company. See Notes
    4 and 7 to Consolidated Financial Statements in the Company's 1996*
    Annual Report to Shareholders for a description of the Company's
    outstanding stock options and convertible debentures. In January and
    April 1996, the Company issued an aggregate of 1,987,273 shares of its
    common stock to Thermo Electron in exchange for 634,049 shares of Thermo
    Voltek common stock and 929,947 shares of Thermo Cardiosystems common
    stock. The shares of common stock were exchanged at their respective fair
    market values on the dates of the transactions. Share information for
    Thermo Cardiosystems and Thermo Voltek has been restated to reflect
    three-for-two stock splits effected in the form of 50% stock dividends,
    distributed in May 1996 and August 1996, respectively. During 1996,
    Thermo Electron purchased 995,800 shares of the Company's common stock in
    the open market for $19,489,000. Additionally, during 1996, Thermo
    Electron purchased in the open market 51,700 shares and 250,000 shares of
    the common stock of Thermo Voltek and Thermo Sentron, respectively, for
    $569,000 and $4,006,000, respectively.

        As of December 28, 1996, the Company owned 54%, 51%, 71%, and 94% of
    the outstanding common stock of Thermo Cardiosystems, Thermo Voltek,
    Thermo Sentron, and Thermedics Detection, respectively. The Company
    intends, for the foreseeable future, to maintain at least 50% ownership
    of these subsidiaries. This may require the Company to purchase
    additional shares of these companies' common stock or, if applicable,
    convertible debentures (which are then converted) from time to time, if
    the number of these companies' outstanding shares increase as a result of
    conversion of convertible obligations, the exercise of stock options
    issued, or otherwise. These or any other purchases by the Company may be
    made either in the open market or directly from Thermo Cardiosystems,
    Thermo Voltek, Thermo Sentron, Thermedics Detection, or Thermo Electron,
    or pursuant to the conversion of all or part of the convertible notes
    issued by Thermo Voltek to the Company. During 1996, the Company
    purchased in the open market 40,000 shares and 291,450 shares of the 



    *  References to 1996, 1995, and 1994 herein are for the fiscal years
       ended December 28, 1996, December 30, 1995, and December 31, 1994,
       respectively.
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    common stock of Thermo Cardiosystems and Thermo Voltek, respectively, for
    $1,219,000 and $4,169,000, respectively.
     
    Forward-looking Statements

        Forward-looking statements, within the meaning of Section 21E of the
    Securities and Exchange Act of 1934, are made throughout this Annual
    Report on Form 10-K. For this purpose, any statements contained herein
    that are not statements of historical fact may be deemed to be
    forward-looking statements. Without limiting the foregoing, the words,
    "believes," "anticipates," "plans," "expects," "seeks," "estimates," and
    similar expressions are intended to identify forward-looking statements.
    There are a number of important factors that could cause the results of
    the Company to differ materially from those indicated by such
    forward-looking statements, including those detailed under the caption
    "Forward-looking Statements" in the Registrant's 1996 Annual Report to
    Shareholders incorporated herein by reference.

    (b) Information About Industry Segments

        Financial information concerning the Company's industry segments is
    summarized in Note 14 to Consolidated Financial Statements in the
    Registrant's 1996 Annual Report to Shareholders and is incorporated
    herein by reference.

    (c) Description of Business

    Instruments and Other Equipment

        Precision-weighing and Inspection Equipment. Thermo Sentron serves
    two principal markets: packaged goods and bulk materials. Thermo
    Sentron's products for the packaged-goods market include a wide range of
    checkweighing equipment and metal detectors that can be integrated at
    various stages in production lines for process control and quality
    assurance. These products are sold primarily to customers in the
    food-processing, pharmaceutical, mail-order, and other industries.
    Products in Thermo Sentron's bulk-material line include conveyor belts,
    scales, solids level-measurement and conveyor-monitoring devices, and
    sampling systems. These products are sold primarily to customers in the
    mining and material-processing industries, as well as electric utilities,
    chemical, and other manufacturing companies.

        During 1996, 1995, and 1994, the Company derived revenues of $70.0
    million, $67.5 million, and $50.1 million, respectively, from its
    precision-weighing and inspection equipment.

        Laboratory Products. To expand its product quality assurance
    offerings, the Company acquired Orion in December 1995. Orion's
    laboratory pH/ion-selective products identify chemical substances found
    in various types of solutions, including foods, pharmaceuticals, soils,
    and water. Pure water monitors, also marketed under the Orion name, use
    ion-selective technology to monitor parameters required for the control
    of high-purity water systems in power generation and other industrial
    applications. Other products include Cahn microweighing and moisture

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    balances and Lear/Fischer filtration/moisture analysis products, all
    marketed under the Orion brand name. Orion also markets consumable
    products for its earlier instruments line.

        During 1996, the Company derived revenues from laboratory products of
    approximately $50.9 million.

        Process Detection Instruments. Thermedics Detection's Alexus system,
    a high-speed product quality assurance system, based on the Company's
    vapor-detection technology, is currently used in bottling lines in the
    beverage industry. In 1996, the Company began selling its high-speed
    X-ray imaging system, marketed under the brand name InScan(TM), to detect
    liquid fill-levels and other parameters for the beverage industry. In
    1996, the Company also introduced a high-speed gas chromatography
    instrument, marketed under the brand name Flash-GC(TM), to provide ultra-
    high-speed, laboratory-quality analysis for near on-line process-control
    applications.

        Thermedics Detection's Moisture Systems and Rutter divisions
    manufacture and sell instruments that use near-infrared spectroscopy to
    measure moisture and other product components, including fat, protein,
    oil, flavorings, solvents, adhesives, and coatings in the manufacturing
    process for the food, pharmaceutical, chemical, wood, pulp, paper,
    textile, and other industries.

        During 1996, 1995, and 1994, the Company derived revenues from its
    process detection instrument business of approximately $34.0 million,
    $18.5 million, and $38.0 million, respectively. 

        Explosives-detection Instruments. Also through Thermedics Detection,
    the Company has developed a line of explosives-detection equipment that
    uses trace-particle and vapor-detection techniques. EGIS is a highly
    sensitive trace-detection instrument used for screening people, baggage,
    packages, freight, and electronic equipment, such as personal computers,
    for the presence of a wide range of explosives, including the plastic
    explosives that have proven difficult to detect using conventional
    methods. EGIS detects ultratrace quantities of certain explosives and
    indicates the concentration and type of explosive detected. EGIS is used
    in 21 countries and operational in 42 international airports. It is also
    used in government buildings, embassies, and other locations where there
    is a high degree of concern for security. The EGIS system has assisted in
    identifying explosives used in terrorist bombings, including those in
    Oklahoma City and at the World Trade Center in New York, as well as in
    Israel, Buenos Aires, and the United Kingdom. Most recently, the Bureau
    of Alcohol, Tobacco, and Firearms and the Federal Bureau of Investigation
    used EGIS systems in their attempt to identify the cause of the crash of
    TWA Flight 800. Thermedics Detection has also developed Rampart(TM), a
    lower-cost product designed for use in conjunction with trace explosives
    detectors such as EGIS, and SecurScan(TM), an automated system that can
    detect traces of explosives on people.

        Electromagnetic Compatibility Testing Instruments. Through its Thermo
    Voltek subsidiary, the Company designs, develops, manufactures, and
    markets electromagnetic compatibility (EMC) testing instruments. Through
    the KeyTek Instrument (KeyTek) division of Thermo Voltek, the Company

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    manufactures instruments that simulate pulsed electromagnetic
    interference (pulsed EMI). Pulsed EMI, caused by natural and man-made
    phenomena such as lightning, static electricity, and electrical power
    disturbances, can damage or disrupt the operation of any product that
    uses digital circuits. Consequently, manufacturers of electronic systems
    and integrated circuits must engineer their products for immunity to
    pulsed EMI. The Company's products are used by these customers primarily
    for product development, design verification, and quality assurance,
    enabling them to meet higher levels of product performance, reliability,
    and safety, and to meet increasingly stringent regulatory requirements,
    including a European Union (EU) directive that took effect on January 1,
    1996.

        Thermo Voltek's Kalmus division manufactures radio frequency (RF)
    power amplifiers. RF power amplifiers are used to test products for
    immunity to conducted and radiated RF interference, another form of
    electromagnetic interference, and are purchased by many of the same
    customers that purchase Thermo Voltek's pulsed EMI testing products.

        Through Thermo Voltek's Comtest subsidiary, the Company provides
    EMC-consulting and systems-integration services, acts as distributor of a
    broad range of EMC-testing products, and manufactures specialized power
    supplies for use in telecommunications equipment.

        In July 1996, Thermo Voltek acquired Pacific Power Source
    Corporation, a manufacturer of programmable power amplifiers that can be
    incorporated into EMC test equipment to assess how well electronics
    tolerate normal variations in the quality and quantity of AC voltage.
    These amplifiers are also used in other kinds of test equipment and in
    application-specific power supplies.

        During 1996, 1995, and 1994, the Company derived revenues of $44.1
    million, $31.6 million, and $19.0 million, respectively, from
    electromagnetic compatibility testing instruments.

        High-voltage Systems. Through Thermo Voltek's Universal Voltronics
    division, the Company designs, manufactures, and markets high-voltage
    power conversion systems, modulators, and related high-voltage equipment
    for industrial, medical, and security processes, as well as for defense
    and scientific research applications. These systems transform
    utility-supplied AC power into the DC voltages and currents required by
    the user and allow precise control over the performance level desired for
    each application.

    Biomedical Products

        Left Ventricular-assist Systems. The Company, through its Thermo
    Cardiosystems subsidiary, has developed two versions of its implantable
    left ventricular-assist system (LVAS): a pneumatic, or air-driven, system
    that can be controlled by an external console and an electric system that
    features an internal electric motor powered by an external battery pack
    worn by the patient. These devices are designed to perform substantially
    all or part of the pumping function of the left ventricle of the natural
    heart for patients suffering from cardiovascular disease. Both of the

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    Company's systems employ the Company's HeartMate(R) blood pump and are
    designed for long-term use.

        Air-driven LVAS. In October 1994, the air-driven LVAS system was
    approved by the FDA for commercial sale in the U.S. for use as a bridge
    to transplant for patients awaiting heart transplantation. This approval
    allows the Company to sell the air-driven LVAS to any of the nearly 900
    cardiac surgery centers in the U.S. In April 1994, the Company received
    the European Conformity Mark (CE Mark), which allows commercial sale of
    the air-driven LVAS in all European Community countries. Clinical trials
    also are under way in the U.S. for the HeartPak portable driver for the
    air-driven HeartMate device.

        Electric LVAS. The Company has also developed an electric LVAS that
    uses the HeartMate blood pump driven by an internal electric motor
    mounted in the blood-pump housing. The system is connected to an external
    battery pack by wires that exit the body, allowing the patient complete
    mobility. The electric LVAS may not be sold commercially in the U.S.
    until it receives approval from the FDA. Clinical trials for the electric
    LVAS as a bridge to transplant are nearing completion and, in December
    1995, the FDA approved the protocol for conducting clinical trials of the
    electric LVAS as an alternative to medical therapy. The trial is expected
    to compare the results of approved patients using the device to a similar
    number using drug therapy. In August 1995, the electric LVAS was awarded
    the CE Mark, allowing commercial sale of this system in all European
    Community countries. In Europe, the electric system is used as a bridge
    to transplant and is also implanted as an alternative to heart
    transplant.

        During 1996, 1995, and 1994, the Company derived revenues of $30.0
    million, $20.6 million, and $10.5 million, respectively, from LVAS.

        In December 1996, Thermo Cardiosystems acquired substantially all of
    the assets, subject to certain liabilities, of Nimbus Medical, Inc.
    (Nimbus), a research and development organization, for $5.0 million in
    cash. Nimbus has been involved in artificial heart technology for more
    than 20 years and has carried out research in two primary fields:
    ventricular-assist devices and total artificial hearts. Nimbus was
    instrumental in developing the basic technology for high-speed rotary
    blood pumps. Because of their smaller size, rotary blood pumps may
    potentially be used to provide cardiac support in smaller adults and in
    children.

        Medical-grade Polymers and Enteral Nutrition-delivery Systems. The
    Company's research relating principally to the development of its LVAS
    has resulted in the development of proprietary medical-grade plastics
    marketed under the names Tecoflex(R) and Tecothane(R). Tecoflex and
    Tecothane are thermoplastic polyurethanes used in medical disposables and
    industrial products. The Company sells Tecoflex and Tecothane in bulk
    form for fabrication by the customer, and the Company also extrudes
    precision tubing to customer specifications.

        In 1993, the Company introduced Scent Seal fragrance samplers, which
    were developed from the Company's polymer technology. Scent Seal
    fragrance samplers are used to hermetically seal a fragrance rendition in

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    perfume advertisements for magazines, and are an alternative to commonly
    used fragrance strips. In June 1995, Thermedics entered into an agreement
    granting Arcade, Inc., the leading manufacturer of scent-sampling
    products, an exclusive, worldwide license to manufacture and distribute
    the Company's fragrance samplers under Thermedics' patents and know-how.
    Under the license agreement, Arcade pays royalties to Thermedics on
    licensed fragrance samplers sold by Arcade, and Thermedics continues to
    provide the polymer gels needed to produce the fragrance samplers. 

        The Company's Corpak Inc. (Corpak) subsidiary designs, manufactures,
    and markets enteral feeding systems that introduce special nutritional
    solutions into the stomach or the small intestine through tubes entering
    the nose or stomach. Enteral therapy is used for patients who are unable
    to feed themselves but who do not require parenteral (intravenous)
    feeding. Corpak's products include bags for nutritional fluids, delivery
    pumps, associated pump sets that hook up to the pumps, and feeding tubes.
    In addition, Corpak markets a range of enteral feeding supplements.

    Raw Materials

        Certain raw materials used in the manufacture of the Company's LVAS
    are available from only one or two suppliers. The Company is making
    efforts to minimize the risks associated with sole sources and ensure
    long-term availability, including qualifying certain alternative
    materials and components or developing alternative sources for the
    materials and components supplied by a single source. Although the
    Company believes that it has adequate supplies of materials and
    components to meet demand for the LVAS for the foreseeable future, no
    assurance can be given that the Company will not experience shortages of
    certain materials or components in the future that could delay shipments
    of the LVAS.

        The cost to the Company to evaluate and test alternative materials
    and components and the time necessary to obtain FDA approval for these
    materials and components are inherently difficult to determine because
    both time and cost are dependent on at least two factors: the similarity
    of the alternative material or component to the original material or
    component, and the amount of third-party testing that may have already
    been completed on alternative materials or components. There can be no
    assurance that the substitution of alternative materials or components
    will not cause delays in the Company's LVAS development program or
    adversely affect the Company's ability to manufacture and ship LVAS to
    meet demand.

    Proprietary Rights

        The Company considers its intellectual property important in the
    operation and growth of its business, and its policy is to protect this
    property through patents, license and confidentiality agreements,
    trademarks, and trade secret protection. The Company applies for and
    maintains patents in the U.S. and in foreign countries, particularly in
    the areas of biomedical materials, medical products, and analytical
    instruments. Although some of these patent rights may provide the Company
    with a competitive advantage, the Company primarily relies on its
    know-how and trade secrets. In addition, there can be no assurance that

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    third parties will not assert claims against the Company that the Company
    infringes the intellectual property rights of such parties. The Company
    could incur substantial costs and diversion of management resources with
    respect to the defense of any such claims, which could have a material
    adverse effect on the Company's business, financial condition, and
    results of operations. Furthermore, parties making such claims could
    secure a judgment awarding substantial damages, as well as injunctive or
    other equitable relief, which could effectively block the Company's
    ability to make, use, sell, distribute, or market its products and
    services in the U.S. or abroad. In the event that a claim relating to
    intellectual property is asserted against the Company, the Company may
    seek licenses to such intellectual property. There can be no assurance,
    however, that such licenses could be obtained on commercially reasonable
    terms, if at all. The failure to obtain the necessary licenses or other
    rights could preclude the sale, manufacture, or distribution of the
    Company's products and, therefore, could have a material adverse effect
    on the Company's business, financial condition, and results of
    operations. Thermo Cardiosystems has received correspondence from a third
    party alleging that the textured surface of the LVAS housing infringes
    certain patent rights of such third party. The third party has offered
    Thermo Cardiosystems a license, which Thermo Cardiosystems has elected
    not to accept. Although Thermo Cardiosystems believes that it has
    meritorious defenses to the claims of the third party, due to the
    inherent uncertainty of litigation, no assurance can be made that Thermo
    Cardiosystems would be successful if any litigation were to begin.

        The Company also has certain licenses to the technology resulting
    from its customer-sponsored development of the Alexus system. The
    Company's patents and agreements have varying lives ranging from one year
    to approximately twenty years, and the Company does not believe that the
    expiration or termination of any one of these patents or agreements would
    materially affect the Company's business.

    Dependency on a Single Customer

        No customer represented 10% or more of the Company's total revenues
    in 1996 and 1995. In 1994, the Company derived 21% of its total revenues
    from The Coca-Cola Company and its affiliates. The Company derived 5% of
    its total revenues in 1994 from Scent Seal Inc., which represented 23% of
    the Biomedical Products segment revenues.

    Backlog

        The Company's backlog of firm orders at year-end 1996 and 1995 was as
    follows:

    (In thousands)                                            1996      1995
    ------------------------------------------------------------------------
    Instruments and Other Equipment                        $39,000  $31,800
    Biomedical Products                                      2,600    2,200
                                                           -------  -------
                                                           $41,600  $34,000
                                                           =======  =======

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        The Company anticipates that substantially all of the backlog at the
    end of 1996 will be shipped or completed during 1997.

    Competition

      Instruments and Other Equipment

        Precision-weighing and Inspection Equipment. The Company's Thermo
    Sentron subsidiary competes with several international and regional
    companies in the markets for its products. Thermo Sentron's competitors
    in the packaged-goods market differ from those in the bulk-materials
    market. The principal competitive factors in both markets are customer
    service and support, quality, reliability, and price.

        Laboratory Products. The Company's Orion division competes with
    several international companies. The Company competes on the basis of
    performance, service, technology, and price.

        Process Detection Instruments. The Company's process detection
    instruments compete with systems manufactured by numerous companies. The
    Company believes that these companies are generally focused on particular
    niches in the process detection systems market, only in some of which
    does the Company compete. Competition in the markets for all of the
    Company's detection products is based primarily on performance, service,
    and price.

        Explosives-detection Instruments. In the explosives-detection market,
    the Company competes with a small number of companies, including other
    markets of chemical trace-detection instruments, and, to a lesser degree,
    makers of enhanced X-ray detectors. Competition in this market is based
    primarily on performance, including speed, accuracy, and the range of
    explosives that can be detected; ease of use; service; and price. The
    Company's principal competitor in the trace detection market is Barringer
    Technologies Inc., a Canadian firm that has placed several trace
    detectors in airport applications. To date, no other manufacturers have
    placed trace detection systems in airports, but the Company expects that
    the Federal Aviation Administration (FAA) will purchase trace systems
    from Barringer and such other manufacturers as part of the initial
    deployment of explosives-detection systems in the U.S. The Company
    believes that the companies, if any, whose devices are ultimately
    required by the FAA will have a substantial competitive advantage in the
    United States.

        Electromagnetic Compatibility Testing Instruments. There are numerous
    companies worldwide that independently manufacture and market pulsed EMI
    test equipment for electronic products and several more that
    independently manufacture and market component-reliability test
    equipment. The Company competes in this market primarily on the basis of
    performance, technical expertise, reputation, and price. In the market
    for RF power amplifiers, competition is based primarily on the basis of
    technical expertise, reputation, and price.

        High-voltage Systems. In the market for high-voltage power supply
    systems of the general type manufactured and marketed by Thermo Voltek,
    the Company competes for both contract and commercial sales primarily on

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    the basis of technical expertise, product performance, reputation, and
    price. Substantially all of the Company's contract and commercial
    revenues are subject to intense competitive bidding. Some of the
    Company's competitors have substantially greater financial resources than
    those of the Company.

      Biomedical Products

        Left Ventricular-assist Systems. The Company is aware of one other
    company that has submitted a PMA application with the FDA for an
    implantable LVAS. The Company is unaware whether this PMA application has
    been accepted for filing by the FDA. Also, the Company is aware of one
    other company that has received approval by the FDA Advisory Panel on
    Circulatory System Devices and subsequent commercial approval for its
    cardiac-assist device. This is a device positioned on the outside of the
    patient's chest and intended for short-term use in the hospital
    environment. In addition, the Company is aware that a total artificial
    heart is currently undergoing clinical trials. The requirement of
    obtaining FDA approval for commercial sale of an LVAS is a significant
    barrier to entry into the U.S. market for these devices. There can be no
    assurance, however, that FDA regulations will not change in the future,
    reducing the time and testing required for others to obtain FDA approval
    for commercial sale. In addition, other research groups and companies,
    some of which have significantly greater resources than those of the
    Company, are developing cardiac systems using alternative technologies or
    concepts, one or more of which might prove functionally equivalent to or
    more suitable than the Company's systems. Among products that have been
    approved for commercial sale, the Company competes primarily on the basis
    of performance, service capability, and price. Competition in the market
    for medical devices is also significantly affected by the reimbursement
    policies of government and private insurers. Any product for which
    reimbursement is not available from third-party payors will be at a
    significant competitive disadvantage.

        Medical-grade Polymers and Enteral Nutrition-delivery Systems. In the
    market for medical-grade polymers and enteral nutrition-delivery systems,
    the Company competes primarily with large pharmaceutical, medical-device,
    and chemical companies, many of which have substantially greater
    financial, technical, and human resources than those of the Company.
    Competition within these markets is intense, and is based primarily on
    price, efficacy, and technological advances.

    Research and Development

        During 1996, 1995, and 1994, the Company expended $17,704,000,
    $11,087,000, and $10,445,000, respectively, on internally sponsored
    research and development programs, and $1,410,000, $3,125,000, and
    $1,702,000, respectively, on research and development programs sponsored
    by others. As of December 28, 1996, 167 professional employees were
    engaged full-time in research and development activities.

    Environmental Protection Regulations

        The Company believes that compliance by the Company with federal,
    state, and local environmental protection regulations will not have a

                                       11PAGE
<PAGE>
    material adverse effect on its capital expenditures, earnings, or
    competitive position.

    Number of Employees

        As of December 28, 1996, the Company's Instruments and Other
    Equipment and Biomedical Products segments employed 1,259 and 305 people,
    respectively.

    (d) Financial Information about Exports by Domestic Operations and about
         Foreign Operations

        Financial information about exports by domestic operations and about
    foreign operations is summarized in Note 14 to Consolidated Financial
    Statements in the Registrant's 1996 Annual Report to Shareholders and is
    incorporated herein by reference.

    (e) Executive Officers of the Registrant

                                  Present Title (Year First Became Executive
    Name                    Age   Officer)
    --------------------    ---   ------------------------------------------
    John W. Wood Jr.        53    President and Chief Executive 
                                    Officer (1984)
    Victor L. Poirier       55    Senior Vice President (1983)
    John T. Keiser          61    Senior Vice President (1994)
    John N. Hatsopoulos*    62    Vice President and Chief Financial
                                    Officer (1983)
    David H. Fine           54    Vice President (1993)
    Jeffrey J. Langan       51    Vice President (1996)
    Paul F. Kelleher        54    Chief Accounting Officer (1985)

    * John N. Hatsopoulos and George N. Hatsopoulos, a director of the
      Company, are brothers.

        Each executive officer serves until his successor is chosen or
    appointed and qualified, or until earlier resignation, death, or removal.
    All executive officers, except Mr. Langan, have held comparable positions
    for at least five years, either with the Company or with its parent
    company, Thermo Electron. Mr. Keiser was appointed senior vice president
    of the Company in 1994, at the same time he was named president of Thermo
    Biomedical, a newly created subsidiary of Thermo Electron. From 1985
    until 1994, Mr. Keiser was president of the Eberline Instrument division
    of Thermo Instrument Systems Inc., a majority-owned public subsidiary of
    Thermo Electron. Mr. Langan was appointed vice president of the Company
    in September 1996, and has been president of Thermedics Detection since
    April 1996 and chief executive officer of Thermedics Detection since
    December 1996. Prior to joining the Company, Mr. Langan held a number of
    positions at the Hewlett-Packard Co., including general manager of the
    Healthcare Information Management Division and Clinical Systems Business
    Division. Messrs. Wood and Fine are full-time employees of the Company.
    Messrs. Hatsopoulos and Kelleher are full-time employees of Thermo
    Electron, and Mr. Poirier is a full-time employee of Thermo
    Cardiosystems, but they devote such time to the affairs of the Company as
    the Company's needs reasonably require.
    
                                       12PAGE
<PAGE>
    Item 2. Properties

        The location and general character of the Company's properties by
    industry segment as of December 28, 1996, are as follows:

    Instruments and Other Equipment

        The Company owns approximately 45,000, 9,500, and 14,300 square feet
    of office, engineering, laboratory, and production space in New York,
    Canada, and Scotland, respectively, and leases approximately 601,000
    square feet of office, engineering, laboratory, and production space
    principally in Minnesota, Massachusetts, California, Washington, Florida,
    Puerto Rico, Mexico, Italy, The Netherlands, Australia, Germany, Spain,
    South Africa, and the United Kingdom, under leases expiring from 1997
    through 2001.

    Biomedical Products

        The Company leases approximately 165,000 square feet of office,
    engineering, laboratory, and production space in Illinois and
    Massachusetts under leases expiring in 1997 through 2013.

        The Company believes that its facilities are in good condition and
    are adequate to meet its current needs and that other suitable space is
    readily available if any of such leases are not extended.


    Item 3. Legal Proceedings

        Not applicable.


    Item 4. Submission of Matters to a Vote of Security Holders

        Not applicable.


                                     PART II

    Item 5. Market for Registrant's Common Equity and Related Stockholder
            Matters

        Information concerning the market and market price for the
    Registrant's Common Stock, $.10 par value, and dividend policy are
    included under the sections labeled "Common Stock Market Information" and
    "Dividend Policy" in the Registrant's 1996 Annual Report to Shareholders
    and is incorporated herein by reference.

                                       13PAGE
<PAGE>
    Item 6. Selected Financial Data

        Information concerning the Registrant's selected financial data is
    included under the sections labeled "Selected Financial Information" and
    "Dividend Policy" in the Registrant's 1996 Annual Report to Shareholders
    and is incorporated herein by reference.


    Item 7. Management's Discussion and Analysis of Financial Condition and
           Results of Operations

        The information required under this item is included under the
    heading "Management's Discussion and Analysis of Financial Condition and
    Results of Operations" in the Registrant's 1996 Annual Report to
    Shareholders and is incorporated herein by reference.


    Item 8. Financial Statements and Supplementary Data

        The Registrant's Consolidated Financial Statements as of December 28,
    1996, are included in the Registrant's 1996 Annual Report to Shareholders
    and are incorporated herein by reference.


    Item 9. Changes in and Disagreements with Public Accountants on
            Accounting and Financial Disclosure

        Not applicable.

                                    PART III


    Item 10. Directors and Executive Officers of the Registrant

        The information concerning directors required under this item is
    incorporated herein by reference from the material contained under the
    caption "Election of Directors" in the Registrant's definitive proxy
    statement to be filed with the Securities and Exchange Commission
    pursuant to Regulation 14A, not later than 120 days after the close of
    the fiscal year. The information concerning delinquent filers pursuant to
    Item 405 of Regulation S-K is incorporated herein by reference from the
    material contained under the heading "Section 16(a) Beneficial Ownership
    Reporting Compliance" under the caption "Stock Ownership" in the
    Registrant's definitive proxy statement to be filed with the Securities
    and Exchange Commission pursuant to Regulation 14A, not later than 120
    days after the close of the fiscal year.


    Item 11. Executive Compensation

        The information required under this item is incorporated herein by
    reference from the material contained under the caption "Executive
    Compensation" in the Registrant's definitive proxy statement to be filed
    with the Securities and Exchange Commission pursuant to Regulation 14A,
    not later than 120 days after the close of the fiscal year.

                                       14PAGE
<PAGE>
    Item 12. Security Ownership of Certain Beneficial Owners and Management

        The information required under this item is incorporated herein by
    reference from the material contained under the caption "Stock Ownership"
    in the Registrant's definitive proxy statement to be filed with the
    Securities and Exchange Commission pursuant to Regulation 14A, not later
    than 120 days after the close of the fiscal year.


    Item 13. Certain Relationships and Related Transactions

        The information required under this item is incorporated herein by
    reference from the material contained under the caption "Relationship
    with Affiliates" in the Registrant's definitive proxy statement to be
    filed with the Securities and Exchange Commission pursuant to Regulation
    14A, not later than 120 days after the close of the fiscal year.


                                     PART IV


    Item 14.Exhibits, Financial Statement Schedules, and Reports on Form 8-K

    (a,d)   Financial Statements and Schedules.

            (1)  The consolidated financial statements set forth in the list
                 below are filed as part of this Report.

            (2)  The consolidated financial statement schedule set forth in
                 the list below is filed as part of this Report.

            (3)  Exhibits filed herewith or incorporated herein by reference
                 are set forth in Item 14(c) below.


            List of Financial Statements and Schedules Referenced in this
            Item 14.

            Information incorporated by reference from Exhibit 13 filed
            herewith:

                 Consolidated Statement of Income
                 Consolidated Balance Sheet
                 Consolidated Statement of Cash Flows
                 Consolidated Statement of Shareholders' Investment
                 Notes to Consolidated Financial Statements
                 Report of Independent Public Accountants

            Financial Statement Schedules filed herewith:

                 Schedule II: Valuation and Qualifying Accounts

            All other schedules are omitted because they are not applicable
            or not required, or because the required information is shown
            either in the financial statements or in the notes thereto.

                                       15PAGE
<PAGE>

    (b)    Reports on Form 8-K.

           None.

    (c)    Exhibits.

           See Exhibit Index on the page immediately preceding exhibits.
























                                       16PAGE
<PAGE>
                                   SIGNATURES

        Pursuant to the requirements of Section 13 or 15(d) of the Securities
    Exchange Act of 1934, the Registrant has duly caused this report to be
    signed by the undersigned, thereunto duly authorized.

    Date: March 14, 1997            THERMEDICS INC.


                                    By: John W. Wood Jr.
                                        ----------------
                                        John W. Wood Jr.
                                        President and Chief Executive 
                                        Officer

        Pursuant to the requirements of the Securities Exchange Act of 1934,
    this report has been signed below by the following persons on behalf of
    the Registrant and in the capacities indicated, as of March 14, 1997.

    Signature                       Title
    ---------                       -----

    By: John W. Wood Jr.            President, Chief Executive Officer,
        ---------------------
        John W. Wood Jr.              and Director

    By: John N. Hatsopoulos         Chairman of the Board, Vice President,
        ---------------------
        John N. Hatsopoulos           Chief Financial Officer, and Director

    By: Paul F. Kelleher            Chief Accounting Officer
        ---------------------
        Paul F. Kelleher

    By: Peter O. Crisp              Director
        ---------------------
        Peter O. Crisp

    By: Paul F. Ferrari             Director
        ---------------------
        Paul F. Ferrari

    By: George N. Hatsopoulos       Director
        ---------------------
        George N. Hatsopoulos

    By: Robert C. Howard            Director
        ---------------------
        Robert C. Howard

    By: Arvin H. Smith              Director
        ---------------------
        Arvin H. Smith

    By: Nicholas T. Zervas          Director
        ---------------------
        Nicholas T. Zervas

                                       17PAGE
<PAGE>
                    Report of Independent Public Accountants
                    ----------------------------------------


    To the Shareholders and Board of Directors of Thermedics Inc.:

        We have audited, in accordance with generally accepted auditing
    standards, the consolidated financial statements included in Thermedics
    Inc.'s Annual Report to Shareholders incorporated by reference in this
    Form 10-K, and have issued our report thereon dated February 6, 1997. Our
    audits were made for the purpose of forming an opinion on those
    statements taken as a whole. The schedule listed in Item 14 on page 15 is
    the responsibility of the Company's management and is presented for
    purposes of complying with the Securities and Exchange Commission's rules
    and is not part of the basic consolidated financial statements. The
    schedule has been subjected to the auditing procedures applied in the
    audits of the basic consolidated financial statements and, in our
    opinion, fairly states in all material respects the consolidated
    financial data required to be set forth therein in relation to the basic
    consolidated financial statements taken as a whole.



                                            Arthur Andersen LLP



    Boston, Massachusetts
    February 6, 1997












                                       18PAGE
<PAGE>
SCHEDULE II


                                 THERMEDICS INC.

                        Valuation and Qualifying Accounts

                                 (In thousands)


                    Balance at  Provision           Accounts            Balance
                     Beginning    Charged  Accounts  Written             at End
Description            of Year to Expense Recovered      Off Other (a)  of Year
------------------- ---------- ---------- --------- -------- --------  --------
Year Ended
 December 28, 1996

  Allowance for
   Doubtful Accounts   $ 3,982    $ 1,352   $   206  $(1,048) $   149   $ 4,641
     

Year Ended
 December 30, 1995

  Allowance for
   Doubtful Accounts   $ 3,640    $   689   $     2  $  (714) $   365   $ 3,982

Year Ended
 December 31, 1994

  Allowance for
   Doubtful Accounts   $   944    $ 1,190   $    60  $(1,271) $ 2,717   $ 3,640

(a) Includes allowance of businesses acquired during the year as described in
    Note 3 to Consolidated Financial Statements in the Registrant's 1996 Annual
    Report to Shareholders and the effect of foreign currency translation.



                                       19PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    -----------------------------------------------------------------------

      2.1     Asset and Stock Purchase Agreement dated as of January 28,
              1994, between Thermo Electron and Baker Hughes
              Incorporated (filed as Exhibit 2.1 to the Registrant's
              Current Report on Form 8-K relating to events occurring on
              March 16, 1994 [File No. 1-9567] and incorporated herein
              by reference).

      2.2     Assignment and Assumption Agreement dated March 16, 1994,
              among Thermo Electron, the Registrant, and Thermo
              Instrument Systems Inc. (filed as Exhibit 2.2 to the
              Registrant's Current Report on Form 8-K relating to events
              occurring on March 16, 1994 [File No. 1-9567] and
              incorporated herein by reference).

      2.3     Agreement and Plan of Merger dated as of November 29,
              1995, by and among the Registrant, ATI Merger Corp.,
              Analytical Technology, Inc., and, for certain limited
              purposes, Thermo Instrument Systems Inc. (filed as Exhibit
              2 to the Registrant's Current Report on Form 8-K relating
              to events occurring on November 29, 1995 [File No. 1-9567]
              and incorporated herein by reference).

      2.4     Asset and Share Purchase Agreement dated as of November
              29, 1995, by and among Thermo Instrument Systems Inc., ATI
              Acquisition Corp., Analytical Technology, Inc., and, for
              certain limited purposes, the Registrant (filed as Exhibit
              10(a) to the Registrant's Current Report on Form 8-K
              relating to events occurring on November 29, 1995 [File
              No. 1-9567] and incorporated herein by reference).

      2.5     Asset Purchase Agreement dated as of January 25, 1996,
              among Thermedics Detection Limited, Moisture Systems
              Corporation, Moisture Systems Limited, and Anacon
              Corporation (filed as Exhibit 2.5 to the Registrant's
              Annual Report on Form 10-K for the fiscal year ended
              December 30, 1995 [File No. 1-9567] and incorporated
              herein by reference). Schedules to this Agreement have
              been omitted pursuant to Rule 601(b)(2) of Regulation S-K.
              The Registrant hereby undertakes to furnish supplementally
              a copy of any omitted schedule to the Commission upon
              request.

      3.1     Articles of Organization (filed as Exhibit 3(a) to the
              Registrant's Annual Report on Form 10-K for the fiscal
              year ended December 31, 1988 [File No. 1-9567] and
              incorporated herein by reference).

      3.2     Amendment to Articles of Organization dated October 25,
              1993 (filed as Exhibit 3(c) to the Registrant's Quarterly
              Report on Form 10-Q for the fiscal quarter ended October
              2, 1993 [File No. 1-9567] and incorporated herein by
              reference).
                                       20PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    -----------------------------------------------------------------------

      3.3     Amended and Restated Articles of Incorporation of the
              Registrant (filed as Exhibit 3(i) to the Registrant's
              Quarterly Report on Form 10-Q for the fiscal quarter ended
              June 29, 1996 [File No. 1-9567] and incorporated herein by
              reference).

      3.4     Amended and Restated By-laws of the Registrant (filed as
              Exhibit 3(c) to the Registrant's Quarterly Report on Form
              10-Q for the fiscal quarter ended March 28, 1992 [File No.
              1-9567] and incorporated herein by reference).

      4.1     Fiscal Agency Agreement dated January 5, 1994, among
              Thermo Cardiosystems, Thermo Electron, and Chemical Bank
              (filed as Exhibit 4.11 to Thermo Cardiosystems' Annual
              Report on Form 10-K for the fiscal year ended January 1,
              1994 [File No. 1-10114] and incorporated herein by
              reference).

      4.2     Fiscal Agency Agreement dated November 19, 1993, among
              Thermo Voltek, Thermo Electron, and Chemical Bank (filed
              as Exhibit 4.3 to Thermo Voltek's Annual Report on Form
              10-K for the fiscal year ended January 1, 1994 [File No.
              1-10574] and incorporated herein by reference).

      4.3     Fiscal Agency Agreement dated as of June 3, 1996, among
              Thermedics, Thermo Electron, and Chemical Bank, as fiscal
              agent (filed as Exhibit 4 to the Registrant's Quarterly
              Report on Form 10-Q for the fiscal quarter ended June 29,
              1996 [File No. 1-9567] and incorporated herein by
              reference).

      4.4     Guarantee Reimbursement Agreement dated February 7, 1994,
              among Thermo Cardiosystems, Thermo Voltek, the Registrant,
              and Thermo Electron (filed as Exhibit 4.4 to the
              Registrant's Annual Report on Form 10-K for the fiscal
              year ended January 1, 1994 [File No. 1-9567] and
              incorporated herein by reference).

              The Registrant hereby agrees, pursuant to Item
              601(b)(4)(iii)(A) of Regulation S-K, to furnish to the
              Commission upon request, a copy of each other instrument
              with respect to other long-term debt of the Company or its
              subsidiaries.

     10.1     Amended and Restated Corporate Services Agreement between
              Thermo Electron and the Registrant dated as of January 3,
              1993 (filed as Exhibit 10(a) to the Registrant's Annual
              Report on Form 10-K for the fiscal year ended January 2,
              1993 [File No. 1-9567] and incorporated herein by
              reference).

                                       21PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    -----------------------------------------------------------------------

     10.2     Lease dated November 1983 between WGO Limited Partnership,
              as Lessor and the Registrant, as Lessee (filed as Exhibit
              10(l) to the Registrant's Registration Statement on Form
              S-1 [Reg. No. 2-96962] and incorporated herein by
              reference; amendments thereto filed as Exhibit 10(l) to
              the Registrant's Annual Report on Form 10-K for the fiscal
              year ended December 31, 1988 [File No. 1-9567] and
              incorporated herein by reference).

      10.3    Thermo Electron Corporate Charter as amended and restated
              effective January 3, 1993 (filed as Exhibit 10(h) to the
              Registrant's Annual Report on Form 10-K for the fiscal
              year ended January 2, 1993 [File No. 1-9567] and
              incorporated herein by reference).

      10.4    Lease dated August 25, 1978, between National Boulevard
              Bank of Chicago and Walpak Company (filed as Exhibit 10(p)
              to the Registrant's Annual Report on Form 10-K for the
              fiscal year ended December 31, 1988 [File No. 1-9567] and
              incorporated herein by reference).

      10.5    Exclusive Base Technology License Agreement between Thermo
              Electron and the Registrant dated January 8, 1988 (filed
              as Exhibit 10(q) to the Registrant's Quarterly Report on
              Form 10-Q for the fiscal quarter ended April 2, 1988 [File
              No. 1-9567] and incorporated herein by reference).

      10.6    Research and Development Contract between Thermo Electron
              and the Registrant dated January 8, 1988 (filed as Exhibit
              10(r) to the Registrant's Quarterly Report on Form 10-Q
              for the fiscal quarter ended April 2, 1988 [File No.
              1-9567] and incorporated herein by reference).

      10.7    Exclusive License and Marketing Agreement between Thermo
              Electron and the Registrant dated January 8, 1988 (filed
              as Exhibit 10(s) to the Registrant's Quarterly Report on
              Form 10-Q for the fiscal quarter ended April 2, 1988 [File
              No. 1-9567] and incorporated herein by reference).

      10.8    Intellectual Property Cross-license Agreement between the
              Registrant and Thermo Cardiosystems (filed as Exhibit
              10(i) to Thermo Cardiosystems' Registration Statement on
              Form S-1 [Reg. No. 33-25144] and incorporated herein by
              reference).

      10.9    Amendment No. 1 dated March 29, 1991, to Exclusive License
              and Marketing Agreement between the Registrant and Thermo
              Electron (filed as Exhibit 10(r) to the Registrant's
              Quarterly Report on Form 10-Q for the fiscal quarter ended
              March 30, 1991 [File No. 1-9567] and incorporated herein
              by reference).

                                       22PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    -----------------------------------------------------------------------

      10.10   Management Agreement by and between Thermo Electron and
              the Registrant dated November 15, 1991 (filed as Exhibit
              10(t) to the Registrant's Annual Report on Form 10-K for
              the fiscal year ended December 28, 1991 [File No. 1-9567]
              and incorporated herein by reference).

      10.11   Agreement dated May 26, 1993, between Thermo Cardiosystems
              and The Polymer Technology Group, Incorporated (filed as
              Exhibit 10(nn) to the Registrant's Quarterly Report on
              Form 10-Q for the fiscal quarter ended July 3, 1993 [File
              No. 1-9567] and incorporated herein by reference).

      10.12   Amended and Restated Master Repurchase Agreement dated as
              of July 2, 1996, between the Registrant and Thermo
              Electron.

      10.13   $38,000,000 Promissory Note dated as of December 11, 1995,
              issued by the Registrant to Thermo Electron (filed as
              Exhibit 10(b) to the Registrant's Current Report on Form
              8-K relating to events occurring on November 29, 1995
              [File No. 1-9567] and incorporated herein by reference).

      10.14   $15,000,000 Promissory Note dated as of February 13, 1996,
              issued by the Company to Thermo Electron (filed as Exhibit
              10 to the Registrant's Quarterly Report on Form 10-Q for
              the fiscal quarter ended March 30, 1996 [File No. 1-9567]
              and incorporated herein by reference).

    10.15-17  Reserved.

      10.18   Incentive Stock Option Plan of the Registrant (filed as
              Exhibit 10(d) to the Registrant's Registration Statement
              on Form S-1 [Reg. No. 33-84380] and incorporated herein by
              reference). (Maximum number of shares issuable in the
              aggregate under this plan and the Registrant's
              Nonqualified Stock Option Plan is 1,931,923 shares, after
              adjustment to reflect share increases approved in 1986 and
              1992, 5-for-4 stock split effected in January 1985,
              4-for-3 stock split effected in September 1985, and
              3-for-2 stock splits effected in October 1986 and November
              1993.)

      10.19   Nonqualified Stock Option Plan of the Registrant (filed as
              Exhibit 10(e) to the Registrant's Registration Statement
              on Form S-1 [Reg. No. 33-84380] and incorporated herein by
              reference). (Maximum number of shares issuable in the
              aggregate under this plan and the Registrant's Incentive
              Stock Option Plan is 1,931,923 shares, after adjustment to
              reflect share increases approved in 1986 and 1992, 5-for-4
              stock split effected in January 1985, 4-for-3 stock split
              effected in September 1985, and 3-for-2 stock splits
              effected in October 1986 and November 1993.)
                                       23PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    -----------------------------------------------------------------------

      10.20   Equity Incentive Plan of the Registrant (filed as Appendix
              A to the Proxy Statement dated May 10, 1993, of the
              Registrant [File No. 1-9567] and incorporated herein by
              reference). (Maximum number of shares issuable is
              1,500,000 shares, after adjustment to reflect 3-for-2
              stock split effected in November 1993.)

      10.21   Thermedics Inc. - Thermedics Detection Inc. Nonqualified
              Stock Option Plan (filed as Exhibit 10.20 to Thermo
              Electron's Annual Report on Form 10-K for the fiscal year
              ended January 2, 1993 [File No. 1-8002] and incorporated
              herein by reference).

      10.22   Thermedics Inc. - Thermo Sentron Inc. Nonqualified Stock
              Option Plan (filed as Exhibit 10.51 to Thermo
              Cardiosystems' Annual Report on Form 10-K for the fiscal
              year ended December 30, 1995 [File No. 1-10114] and
              incorporated herein by reference).

      10.23   Thermedics Inc. - Thermo Cardiosystems Inc. Nonqualified
              Stock Option Plan (filed as Exhibit 4(b) to Thermo
              Cardiosystems' Registration Statement on Form S-8 [Reg.
              No. 33-45282] and incorporated herein by reference).

      10.24   Directors Stock Option Plan of the Registrant (filed as
              Exhibit 10.20 to the Registrant's Annual Report on Form
              10-K for the fiscal year ended December 31, 1994 [File No.
              1-9567] and incorporated herein by reference).

      10.25   Deferred Compensation Plan for Directors of the Registrant
              (filed as Exhibit 10(g) to the Registrant's Registration
              Statement on Form S-1 [Reg. No. 33-96962] and incorporated
              herein by reference).

              In addition to the stock-based compensation plans of the
              Registrant, the executive officers of the Registrant may
              be granted awards under stock-based compensation plans of
              Thermo Electron for services rendered to the Registrant or
              to such affiliated corporations. Thermo Electron's plans
              were filed as Exhibits 10.21 through 10.44 to the Annual
              Report on Form 10-K of Thermo Electron for the year ended
              December 30, 1995 [File No. 1-8002] and as Exhibit 10.19
              to the Annual Report on Form 10-K of Trex Medical
              Corporation for the fiscal year ended September 28, 1996,
              [File No. 1-11827] and are incorporated herein by
              reference.

      10.26   Restated Stock Holdings Assistance Plan and Form of
              Promissory Note.

                                       24PAGE
<PAGE>
                                  EXHIBIT INDEX

    Exhibit
    Number    Description of Exhibit
    -----------------------------------------------------------------------

       11     Statement re: Computation of Earnings per Share.

       13     Annual Report to Shareholders for the year ended December
              28, 1996 (only those portions incorporated herein by
              reference).

       21     Subsidiaries of the Registrant.

       23     Consent of Arthur Andersen LLP.

       27     Financial Data Schedule.