PRESS RELEASE:

                                             Filer:  Thermo Electron Corporation
                                               Subject Company:  Thermedics Inc.
                                  Subject Company Exchange Act File No.:  1-9567
                                   Registration Statement No.:  333-____________
Investor Contact: 781-622-1111
Media Contact: 781-622-1252

               THERMO ELECTRON ANNOUNCES MAJOR REORGANIZATION PLAN

*        Company to be Split into Three Independent Entities: Thermo Electron to
         Focus on Measurement and Detection Instruments; Thermo Fibertek and
         Medical Products Businesses to be Spun Off as Dividends to Thermo
         Electron Shareholders

*        Businesses with Aggregate Revenues of $1.2 Billion to be Sold

WALTHAM, Mass., January 31, 2000 - Thermo Electron Corporation (NYSE-TMO)
announced today that its board of directors has authorized a major
reorganization plan that will vastly simplify Thermo Electron by splitting the
company into three independent public entities, two of which will be spun off as
dividends to Thermo Electron shareholders. As part of the plan, which is
expected to take about one year to complete, the company has designated for sale
businesses with aggregate revenues of $1.2 billion. This is in addition to
businesses with approximately $150 million in revenues sold since May 1999.
Ultimately, Thermo Electron will become one integrated, publicly traded company.

         The "new" Thermo Electron will focus on its core business - measurement
and detection instruments. Thermo Electron also plans to spin off as a dividend
to Thermo Electron shareholders its Thermo Fibertek subsidiary and a newly
created medical products company. As a stand-alone public entity, Thermo
Fibertek will continue to broaden the use of its separation technologies for
process industries and commercialize new fiber-based composite products. The new
medical products company, which will be formed by combining several existing
businesses, will provide medical equipment and systems to the healthcare
industry. Once the process is complete, each of these three companies will have
its own entirely separate and independent board of directors and management
team.

         Richard F. Syron, chairman, president, and chief executive officer of
Thermo Electron, said, "This is a bold plan to deliver shareholder value by
creating three independent, focused companies that have strong prospects for
growth. Further, we believe this plan will allow the 'new' Thermo Electron to
become the preeminent provider of measurement and detection instruments. Thermo
Electron will be a highly integrated, tightly managed operating company. While
still a broad-based instrument company addressing needs in virtually every
industry, we plan to invest significant resources - through internal R&D,
strategic partnerships, and complementary acquisitions - in growing our
expanding product and technology portfolio serving customers in the life
sciences and telecommunications industries.

         "In addition, we believe we will create added value for Thermo Electron
shareholders by spinning off two focused companies that also have substantial
opportunities for growth. Shareholders who have struggled in the past with the
company's complexity should benefit from the simplified structure and
well-defined strategy. Each of the three entities that will emerge from this
plan has the scale and business fundamentals to be a strong, stand-alone
company," said Syron. "With a clear mission and approach, each management team
will be able to concentrate on the specific issues and needs facing the
customers it serves. As independent entities, these companies will have greater
access to capital, which, in turn, will enable them to build on their leading
market positions. We believe this will allow each company to become a superior
competitor, thereby offering greater value to customers and shareholders."

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Thermo Electron Corporation                                                    2

         Syron concluded, "Thermo Electron was founded on the principle of
identifying and nurturing new technologies and bringing them to the marketplace.
With this new structure, we believe each company will be able to continue the
Thermo Electron tradition of product innovation and excellence, while creating
even greater opportunities for commercial success."

The three new companies that will be formed from Thermo Electron are:

THERMO ELECTRON - MEASUREMENT AND DETECTION INSTRUMENTS:
Thermo Electron will focus solely on its measurement and detection instruments
business. Thermo Electron is already a world leader in the instrument industry,
with 1999 instrument revenues of approximately $2.3 billion. The "new" Thermo
Electron will provide instruments for the life sciences, telecommunications,
analytical, process control, laser, optical components, precision
temperature-control, and environmental-monitoring markets. Currently these
technologies are designed and distributed through a number of public and private
companies, including Thermo Instrument Systems and its subsidiaries: Thermo
Optek, ThermoQuest, Thermo BioAnalysis, ONIX Systems, ThermoSpectra, Metrika
Systems, Thermo Vision, and Thermo Environmental Instruments, as well as through
Thermedics Detection and Thermo Sentron. Under the plan, public subsidiaries
would be "spun in" or merged into Thermo Electron, ultimately creating one
integrated public company.

         Spectra-Physics Lasers, acquired by Thermo Instrument in February 1999,
will remain a public company while Thermo Electron continues to evaluate this
business.

         Richard Syron will remain chairman, president, and chief executive
officer of Thermo Electron, and Earl R. Lewis will continue to serve as
president of the instruments business.

THERMO FIBERTEK - SEPARATION TECHNOLOGIES AND FIBER-BASED PRODUCTS:
Thermo Fibertek is a leading provider of separation technologies for the pulp
and paper industries and is known for its service, product quality, and
technological innovation. The company is a worldwide leader in recycling
equipment and water-management systems, and the number one competitor worldwide
for paper-machine accessories. As an independent company, Thermo Fibertek will
be better positioned to raise capital for investment in additional technologies
and businesses that would allow it to expand its core business. Thermo Fibergen,
which will remain a subsidiary of Thermo Fibertek after the proposed spinoff,
will aggressively fund the continued development and growth of its fiber-based
composite business. In 1999, the companies had consolidated sales of
approximately $225 million.

         Thermo Fibertek's obligations relating to its outstanding convertible
debentures will not be affected by the spinoff; the debentures will remain
convertible into Thermo Fibertek common stock and will continue to be guaranteed
by Thermo Electron.

         William A. Rainville will remain president and chief executive officer
of Thermo Fibertek. The company is expected to be renamed before the spinoff to
shareholders, which is anticipated to occur by early 2001.

MEDICAL PRODUCTS:
Thermo Electron has had a growing presence in the medical products industry
through a number of wholly owned businesses and public subsidiaries. Currently,
Thermo Electron is the number one player

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Thermo Electron Corporation                                                    3


in neurodiagnostic and monitoring equipment, and holds the number two position
worldwide in respiratory and pulmonary care products. Several of Thermo
Electron's healthcare businesses will become part of a new medical products
company that will include its neurodiagnostic, patient-monitoring, auditory,
respiratory and pulmonary care, enteral feeding systems, and medical polymers
product lines. In 1999, these businesses had sales of approximately $335
million. As an independent, focused entity, the new medical products company
will be better positioned to market its products and respond to customer demands
in today's competitive healthcare arena. Thermo Cardiosystems and Trex Medical
will not be part of the new medical products company. See "Divestitures" below.

         Thermo Electron is currently conducting an extensive search for a
president and chief executive officer of this new medical products company,
considering both internal and external candidates. The company will fill the
position before the spinoff to shareholders, which is expected to occur by early
2001.

DIVESTITURES:
Over the next 12 months, the company also plans to sell businesses with
aggregate sales of approximately $1.2 billion. This is in addition to businesses
with approximately $150 million in revenues sold since May 1999. Thermo Electron
believes that these businesses would better prosper within other strategically
aligned organizations that can provide greater focus, resources, and targeted
marketing strength. The additional businesses that are expected to be sold
include, among others, the following: Thermo Cardiosystems, Trex Medical, the
Thermo TerraTech businesses, Thermo Coleman, Peek, NuTemp, Thermo Trilogy, and
Peter Brotherhood. In the aggregate, the company does not currently expect to
incur losses from the disposition of these businesses.

         The proceeds from these divestitures will be retained by Thermo
Electron for reinvestment in future acquisitions and product development efforts
related to measurement and detection instruments.

SPIN-INS:
Thermo Electron has already announced the terms for, and is proceeding with, the
spin-ins of ThermoTrex, ThermoLase, Thermo TerraTech, ThermoRetec, and The
Randers Killam Group. Under the plan, Thermo Electron would also spin in Thermo
Optek, ThermoQuest, Thermo BioAnalysis, Metrika Systems, ONIX Systems, Thermo
Instrument Systems, Thermedics, and as previously announced, Thermo Sentron,
Thermedics Detection, and Thermo Ecotek - described in brief below.

THE THERMO INSTRUMENT GROUP: Because Thermo Instrument Systems currently owns
more than 90 percent of the outstanding shares of Thermo Optek and ThermoQuest
common stock, each of these two companies is expected to be spun in for cash
through a "short-form" merger, at $15.00 and $17.00 per share, respectively.

         In addition, Thermo Instrument will make cash tender offers of $28.00
per share for Thermo BioAnalysis, $9.00 per share for Metrika Systems, and $9.00
per share for ONIX Systems, in order to bring its own equity ownership in each
of these businesses to at least 90 percent. If successful, each of these
companies would then be spun into Thermo Instrument through a short-form merger
at the same cash prices as the tender offers.


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Thermo Electron Corporation                                                    4


         Following these tender offers, Thermo Instrument, in turn, would be
taken private. Thermo Electron plans to conduct an exchange offer, in which
Thermo Electron common stock would be offered to Thermo Instrument minority
shareholders in exchange for their Thermo Instrument common stock in order to
bring Thermo Electron's equity ownership in Thermo Instrument to at least 90
percent. If successful, Thermo Instrument would then be spun into Thermo
Electron through a short-form merger. Thermo Instrument minority shareholders
would also receive shares of Thermo Electron common stock in exchange for their
Thermo Instrument shares in the merger at the same exchange ratio that is being
offered in the exchange offer. The company expects to announce the exchange
ratio for this transaction shortly after conducting the tender offers for Thermo
BioAnalysis, Metrika Systems, and ONIX Systems.

THE THERMEDICS GROUP: Thermedics will make cash tender offers of $8.00 per share
for Thermedics Detection and $15.50 per share for Thermo Sentron in order to
bring its own equity ownership in each of these companies to at least 90
percent. If successful, each of these companies would then be spun into
Thermedics through a short-form merger at the same cash prices as the tender
offers.

         Following these tender offers, Thermedics, in turn, would be taken
private. Thermo Electron plans to conduct an exchange offer, in which Thermo
Electron common stock would be offered to Thermedics minority shareholders in
exchange for their Thermedics common stock, in order to bring Thermo Electron's
equity ownership in Thermedics to at least 90 percent. If successful, Thermedics
would then be spun into Thermo Electron through a short-form merger. Thermedics
minority shareholders would also receive shares of Thermo Electron common stock
in exchange for their Thermedics shares in the merger at the same exchange ratio
that is being offered in the exchange offer. The company expects to announce the
exchange ratio for this transaction shortly after conducting the tender offers
for Thermedics Detection and Thermo Sentron.

THERMO ECOTEK: Because Thermo Electron currently owns more than 90 percent of
the outstanding shares of Thermo Ecotek common stock, Thermo Electron will spin
in this company through a short-form merger. Thermo Ecotek minority shareholders
will receive 0.431 shares of Thermo Electron common stock in exchange for each
share of Thermo Ecotek stock held. Under Thermo Electron's new focused strategy,
Thermo Ecotek is no longer a core business, and Thermo Electron is evaluating
its strategic options for this company. In the meantime, Thermo Ecotek will
proceed with its ongoing power projects using its own resources to fund
development.

         Upon completion of the respective spin-ins, outstanding obligations
under the Thermo Instrument, Thermedics, and Thermo Ecotek convertible
debentures will be assumed by Thermo Electron, and these debentures will become
convertible into Thermo Electron common stock. Thermo Electron's guarantee
obligations under other subsidiary debentures and its obligations under its own
debentures will remain ongoing obligations of Thermo Electron.

TIMING:
Thermo Instrument and Thermedics expect to conduct their respective subsidiary
tender offers during the second quarter of 2000. The Thermo Optek, ThermoQuest,
and Thermo Ecotek short-form mergers are expected to be completed by the end of
the second quarter of 2000. Thermo Electron expects to conduct the exchange
offers for Thermo Instrument and Thermedics during the third quarter of 2000.


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Thermo Electron Corporation                                                    5


         The spinoffs of Thermo Fibertek and the new medical products company,
as well as the planned divestitures, are expected to take up to a year to
complete.

Thermo Electron's board has been advised by McKinsey & Company, Inc.; J.P.
Morgan & Co., Inc.; and The Beacon Group Capital Services, LLC in its
development of this plan.

CONDITIONS:
All of the transactions described here are subject to a number of conditions,
including the following.

         The proposed spinoffs of Thermo Fibertek and the new medical products
company will require: a favorable ruling by the Internal Revenue Service
regarding the tax treatment of the spinoffs; Securities and Exchange Commission
(SEC) clearance of necessary filings; final Thermo Electron board action; and
other customary conditions. In addition, the spinoff of the new medical products
company will be conditioned on the successful completion of the proposed Thermo
Instrument and Thermedics spin-ins.

         The spin-ins of Thermo Optek, ThermoQuest, and Thermo Ecotek will
require SEC clearance of necessary filings. The tender offers for Thermo
BioAnalysis, Metrika Systems, ONIX Systems, Thermo Sentron, and Thermedics
Detection, as well as the proposed exchange offers for Thermo Instrument and
Thermedics, will require: establishment of exchange ratios for the proposed
Thermo Instrument and Thermedics exchange offers; the receipt of acceptances
from enough minority shareholders so that Thermo Instrument's, Thermedics', or
Thermo Electron's (as applicable) equity ownership in each of the proposed
spin-in companies reaches at least 90 percent; and other customary conditions.
In addition, depending on the exchange ratio that is set, and the number of
Thermo Electron shares outstanding at the time of the transaction, the issuance
of Thermo Electron common stock in the Thermo Instrument spin-in may require the
approval of Thermo Electron's shareholders, per New York Stock Exchange rules.

OTHER IMPORTANT INFORMATION:
THE TRANSACTIONS DESCRIBED IN THIS ANNOUNCEMENT HAVE NOT YET COMMENCED. AS SOON
AS WE COMMENCE OUR EXCHANGE OFFERS FOR THERMO INSTRUMENT AND THERMEDICS, WE WILL
FILE TENDER OFFER STATEMENTS AND REGISTRATION STATEMENTS ON FORM S-4 WITH THE
SEC. IN ADDITION, WE HAVE NOT YET FILED A REGISTRATION STATEMENT WITH RESPECT TO
THE SHARES TO BE ISSUED TO THE MINORITY SHAREHOLDERS OF THERMO ECOTEK. YOU
SHOULD READ EACH OF THESE DOCUMENTS WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL
CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTIONS. YOU CAN OBTAIN
THE TENDER OFFER STATEMENTS, REGISTRATION STATEMENTS, AND OTHER DOCUMENTS THAT
ARE FILED WITH THE SEC FOR FREE WHEN THEY ARE AVAILABLE ON THE SEC'S WEB SITE AT
http://www.sec.gov. IF YOU WRITE US OR CALL US, WE WILL SEND YOU THESE DOCUMENTS
FOR FREE WHEN THEY ARE AVAILABLE, AS APPLICABLE TO THE PARTICULAR TRANSACTION:

*      TENDER OFFER STATEMENTS (EXCEPT FOR EXHIBITS)
*      REGISTRATION STATEMENTS ON FORM S-4
*      OFFERS TO PURCHASE
*      LETTERS OF TRANSMITTAL
*      NOTICES OF GUARANTEED DELIVERY




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Thermo Electron Corporation                                                    6


YOU CAN CALL US AT (781) 622-1111 OR WRITE TO US AT:

     INVESTOR RELATIONS DEPARTMENT
     THERMO ELECTRON CORPORATION
     81 WYMAN STREET, P.O. BOX 9046
     WALTHAM, MA 02454-9046

IN ADDITION, THE TENDER OFFERS TO BE CONDUCTED BY THERMO INSTRUMENT FOR THERMO
BIOANALYSIS, METRIKA SYSTEMS, AND ONIX SYSTEMS, AND BY THERMEDICS FOR THERMEDICS
DETECTION AND THERMO SENTRON, AS DESCRIBED IN THIS ANNOUNCEMENT, HAVE NOT YET
COMMENCED. AS SOON AS THOSE TENDER OFFERS COMMENCE, THERMEDICS AND THERMO
INSTRUMENT, RESPECTIVELY, WILL FILE TENDER OFFER STATEMENTS JOINTLY WITH THERMO
ELECTRON WITH THE SEC. YOU SHOULD READ THE TENDER OFFER STATEMENTS WHEN THEY
BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE
TENDER OFFERS. YOU CAN OBTAIN THE TENDER OFFER STATEMENTS AND OTHER DOCUMENTS
THAT ARE FILED WITH THE SEC FOR FREE WHEN THEY ARE AVAILABLE ON THE SEC'S WEB
SITE AT http://www.sec.gov. IF YOU WRITE US OR CALL US AT THE ABOVE ADDRESS OR
PHONE NUMBER, WE WILL SEND YOU THESE DOCUMENTS FOR FREE WHEN THEY ARE AVAILABLE:

*      TENDER OFFER STATEMENTS (EXCEPT FOR EXHIBITS)
*      OFFERS TO PURCHASE
*      LETTERS OF TRANSMITTAL
*      NOTICES OF GUARANTEED DELIVERY

The following constitutes a "Safe Harbor" statement under the Private Securities
Litigation Reform Act of 1995: This press release contains forward-looking
statements that involve a number of risks and uncertainties. Important factors
that could cause actual results to differ materially from those indicated by
such forward-looking statements are set forth under the heading "Forward-looking
Statements" in Exhibit 13 to the company's annual report on Form 10-K, for the
year ended January 2, 1999. These include risks and uncertainties relating to:
the company's spinout and acquisition strategies, competition, international
operations, technological change, possible changes in governmental regulations,
capital spending and government funding policies, dependence on intellectual
property rights, and the potential impact of the year 2000 on processing
date-sensitive information.


SCRIPT:

Talking Points for Conference Call, January 31, 2000

We are announcing today a bold plan to deliver shareholder value by splitting
the company into three independent entities - vastly simplify Thermo Electron

     There are three components:

     1.   Spinning in almost all remaining public subsidiaries

     2.   Spinning off to shareholders two companies:  Thermo Fibertek and newly
          created Medical Products company

     3.   Selling businesses with approximately $1.2 billion in revenues

     Ultimately - when all is said and done - Thermo Electron will become ONE
     integrated, publicly traded company


     -    TMO  shareholders  should  have added value by owning  three  entirely
          independent and separate companies:

          Each focused on its own customers and markets

          Each with strong competitive positions in the markets they address

          Each with solid growth prospects

     -    Spin-ins and spinoffs will  eliminate  structural  complexity - easier
          for both shareholders and managers

     -    TMO will focus solely on core measurement and detection business

     -    Divestitures  will  generate  significant  cash to support  aggressive
          growth plans for the  measurement and detection  instruments  business
          - fund internal growth and acquisitions

     -    Goal is to become pre-eminent global instrument company

     -    Emerge as one highly integrated company


                                       1



     This plan is result of six months of complete review of Thermo's operations
     with help of McKinsey, J.P. Morgan, and the Beacon Group:

     -    Everything  was on table in review of our  businesses - we  considered
          every major alternative

     -    Our sole objective:  create value for shareholders - this one, by far,
          will offer the most value to shareholders


     Timeframe:

     -    We  recognize  speed is very  important - so we are  proceeding  on an
          accelerated basis

     -    We have outlined in this plan  definitive  time frames and  definitive
          steps


     Spin-ins:

     -    Essentially completed: 9 of the 12 transactions announced in May

     -    Today we have  announced  the terms for the 3 remaining  deals pending
          from May

     -    As well as 7 new spin-ins

     -    We announced terms for 8 spin-ins this morning - 7 cash and 1 stock

     -    Our goal is to complete 7 cash spin-ins in Q2 - and to complete  other
          3 spin-ins in Q3



                                       2




     Spin-offs:

     -    We are announcing the spin-off of Fibertek/Fibergen  and a new Medical
          Products company, created by combining many of our existing businesses

     -    Need  favorable  letter ruling from IRS - Had a positive  meeting with
          IRS to review our plans

     -    Time frame largely  dictated by IRS: expect to complete  spinoffs late
          2000 or early 2001


     Divestitures:

     -    We are  announcing  divestitures  of businesses  with revenues of $1.2
          billion

     -    We expect these  divestitures to generate proceeds of approximately $1
          billion

     -    Already generated  approximately  $180 million in pretax proceeds from
          divestitures we've completed since May

     -    Starting  to  work  immediately  on new  divestitures  and  expect  to
          complete deals within one year - some already underway

     -    Selling many excellent  businesses  (e.g.  Cardio and Retec) that have
          strong prospects but will fit better with more  strategically  aligned
          owner


     Thermo Ecotek

     -    Committed to spin-in, but under new focused strategy, no longer a core
          business. Continuing to evaluate strategic options

     -    Ecotek will  proceed  with its ongoing  power  projects  using its own
          resources to fund development


                                       3




Thermo  Electron  shareholders  will own  shares  in three  strong,  independent
companies:


     Fibertek

     -    Almost $250 million in revenues with strong core  business  addressing
          paper  industry  and  exciting   Fibergen  new  venture   focusing  on
          fiber-based composite materials

     -    Core business  excellent  bookings Q3+Q4, and rebounding from slump in
          paper market

     -    Better  able to raise  capital to expand  into other  industries  with
          separation technology

     -    Large upside  potential  with  Fibergen's  new  fiber-based  composite
          materials.  Fibergen  just  starting  to  sell  its new  plastic  wood
          product.  Fibergen  has  proprietary  process  to  create  competitive
          product with very strong specs that addresses large potential market.


     Medical Products company

     -    Approximately   $350   million  in  revenues   consisting   mostly  of
          respiratory  and  pulmonary  care, as well as in  neurodiagnostic  and
          patient monitoring businesses.

     -    Strong  niche  positions  -  #1  in  neurodiagnostic   and  monitoring
          equipment  (lots of potential with new trend toward  telemedicine  and
          remote  monitoring) and #2 in respiratory and pulmonary care products,
          highly profitable businesses

     -    Now will be managed for higher revenue growth

     -    Started  search  for  CEO  with  strong  medical   products   industry
          background


                                       4





The New Thermo Electron - Measurement and Detection Instruments

     -    Roughly $2.5 billion  company with strong  position in many markets it
          addresses

     -    If you  look  at  the  current  market  valuation  of our  instruments
          business compared to our principal  competitors,  you will see that we
          are substantially undervalued

     -    Strong growth  prospects,  particularly  in our businesses  that serve
          customers in life sciences and telecommunication industries.

     -    We plan to invest significant resources in expanding these two areas -
          through  internal  R&D,  strategic  partnerships,   and  complementary
          acquisitions

     -    And we will have the money to do it - nearly a  billion  dollars  from
          divestitures



Thermo Electron vision is very clear and straightforward:

To channel ALL our resources - financial,  human, and  technological - to become
the  preeminent  provider of measurement  and detection  instruments in exciting
markets, such as life sciences and telecommunications


     -    Thermo  Electron   tradition  of  product  innovation  and  excellence
          continues

     -    Our  mission  remains  the same:  use  technology  to solve  society's
          pressing  problems by identifying and bringing new technologies to the
          marketplace and providing superior value to our customers

     -    Renewed focus on growth - with an emphasis on internal growth

Thermo  Electron  is poised to deliver  value to  shareholders,  employees,  and
customers - We're very  excited  about this plan and have already hit the ground
running

OTHER IMPORTANT INFORMATION:
THE TRANSACTIONS DESCRIBED IN THIS ANNOUNCEMENT HAVE NOT YET COMMENCED. AS SOON
AS WE COMMENCE OUR EXCHANGE OFFERS FOR THERMO INSTRUMENT AND THERMEDICS, WE WILL
FILE TENDER OFFER STATEMENTS AND REGISTRATION STATEMENTS ON FORM S-4 WITH THE
SEC. IN ADDITION, WE HAVE NOT YET FILED A REGISTRATION STATEMENT WITH RESPECT TO
THE SHARES TO BE ISSUED TO THE MINORITY SHAREHOLDERS OF THERMO ECOTEK. YOU
SHOULD READ EACH OF THESE DOCUMENTS WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL
CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTIONS. YOU CAN OBTAIN
THE TENDER OFFER STATEMENTS, REGISTRATION STATEMENTS, AND OTHER DOCUMENTS THAT
ARE FILED WITH THE SEC FOR FREE WHEN THEY ARE AVAILABLE ON THE SEC'S WEB SITE AT
http://www.sec.gov. IF YOU WRITE US OR CALL US, WE WILL SEND YOU THESE DOCUMENTS
FOR FREE WHEN THEY ARE AVAILABLE, AS APPLICABLE TO THE PARTICULAR TRANSACTION:

*      TENDER OFFER STATEMENTS (EXCEPT FOR EXHIBITS)
*      REGISTRATION STATEMENTS ON FORM S-4
*      OFFERS TO PURCHASE
*      LETTERS OF TRANSMITTAL
*      NOTICES OF GUARANTEED DELIVERY

YOU CAN CALL US AT (781) 622-1111 OR WRITE TO US AT:

     INVESTOR RELATIONS DEPARTMENT
     THERMO ELECTRON CORPORATION
     81 WYMAN STREET, P.O. BOX 9046
     WALTHAM, MA 02454-9046

IN ADDITION, THE TENDER OFFERS TO BE CONDUCTED BY THERMO INSTRUMENT FOR THERMO
BIOANALYSIS, METRIKA SYSTEMS, AND ONIX SYSTEMS, AND BY THERMEDICS FOR THERMEDICS
DETECTION AND THERMO SENTRON, AS DESCRIBED IN THIS ANNOUNCEMENT, HAVE NOT YET
COMMENCED. AS SOON AS THOSE TENDER OFFERS COMMENCE, THERMEDICS AND THERMO
INSTRUMENT, RESPECTIVELY, WILL FILE TENDER OFFER STATEMENTS JOINTLY WITH THERMO
ELECTRON WITH THE SEC. YOU SHOULD READ THE TENDER OFFER STATEMENTS WHEN THEY
BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE
TENDER OFFERS. YOU CAN OBTAIN THE TENDER OFFER STATEMENTS AND OTHER DOCUMENTS
THAT ARE FILED WITH THE SEC FOR FREE WHEN THEY ARE AVAILABLE ON THE SEC'S WEB
SITE AT http://www.sec.gov. IF YOU WRITE US OR CALL US AT THE ABOVE ADDRESS OR
PHONE NUMBER, WE WILL SEND YOU THESE DOCUMENTS FOR FREE WHEN THEY ARE AVAILABLE:

*      TENDER OFFER STATEMENTS (EXCEPT FOR EXHIBITS)
*      OFFERS TO PURCHASE
*      LETTERS OF TRANSMITTAL
*      NOTICES OF GUARANTEED DELIVERY


                                       5