Exhibit 21
THERMO ELECTRON CORPORATION

Subsidiaries of the Registrant

At February 28, 1999, the Registrant owned the following companies:

STATE OR REGISTRANT'S
JURISDICTION OF PERCENT OF
NAME INCORPORATION OWNERSHIP
- ----------------------------------------------------------------------------------------------------------

Thermo Coleman Corporation Delaware 87.19**
Coleman Research Corporation Florida 100
Coleman Services Incorporated Delaware 100
Thermo Information Solutions Inc. Delaware 79.29**
Tera Systemes s.a.r.l. France 100
Thermo Info France S.A. France 100
Thermo Info UK Limited United Kingdom 100
Traveller Information Services, Inc. Alabama 75
Nicolet Biomedical Inc. California 100
Eden Medical Electronics, Inc. Delaware 100
Grason-Stadler, Inc. Massachusetts 100
Neuroscience Limited United Kingdom 100
Nicolet Biomedical Japan Inc. Japan 100
Nicolet Biomedical Ltd. United Kingdom 100
Nicolet Biomedical S.A.R.L. France 100
Nicolet - EME GmbH Germany 100
Nicolet Vascular Inc. Delaware 100
ILS, Inc. Delaware 100
IMEX International, Inc. Colorado 100
Peter Brotherhood Holdings Ltd. United Kingdom 100
Aircogen Ltd. United Kingdom 80
Peter Brotherhood Limited United Kingdom 100
D.S.T. Pattern & Engineering Co. Ltd. United Kingdom 100
Link Control Technology Ltd. United Kingdom 100
Peter Brotherhood Pension Fund Trustees Ltd. United Kingdom 100
Thermo Electron Realty Limited United Kingdom 100
Thermo Holdings Limited United Kingdom 100
SensorMedics Corporation Delaware 100
SensorMedics B.V. Netherlands 100
SensorMedics (Deutschland) GmbH Germany 100
SensorMedics FSC Corporation Virgin Islands 100
Thermo Electron, S.A. de C.V. Mexico 100
The Thermo Electron Companies Inc. Wisconsin 100
Bear Medical Systems Inc. Delaware 100
Bird Medical Technologies, Inc. California 100
Bird International, Inc. U.S. Virgin Islands 100
Bird Products Corporation California 100
Bird Life Design Corporation California 100
Stackhouse, Inc. California 100
Gulf Precision, Inc. Arizona 100
Seeley Enterprises, Inc. New Mexico 100
ITC Holdings Inc. Delaware 100
Loftus Furnace Company Pennsylvania 100

Medical Data Electronics, Inc. Delaware 100
Met-Therm, Inc. Ohio 100
NAPCO, Inc. Connecticut 100
Nicolet Biomedical of California Inc. California 100
North East Surgical Tool Corp. Massachusetts 100
North Carbondale Minerals, Inc. California 100
Overly, Inc. Wisconsin 100
Perfection Heat Treating Company Michigan 100
San Marcos Resource Recovery, Inc. California 100
Southern Ocean County Resource Recovery, Inc. New Jersey 100
Staten Island Cogeneration Corporation New York 100
TE Great Lakes Inc. Michigan 100
TEC Cogeneration Inc. Florida 100
South Florida Cogeneration Associates Florida 50*
TEC Energy Corporation California 100
North County Resource Recovery Associates California 100*
(50% of which is owned directly by
San Marcos Resource Recovery, Inc.)
Tecomet Inc. Massachusetts 100
Thermedics Inc. Massachusetts 73.98**
Corpak Inc. Massachusetts 100
Walpak Company Illinois 100
TV Acquisition Corporation Delaware 100
TMD Holdings Inc. Delaware 100
TMO TCA Holdings, Inc. Delaware 100
Thermedics Detection Inc. Massachusetts 83.79**
(additionally, 4.57%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
Detection Securities Corporation Massachusetts 100
Orion Research, Inc. Massachusetts 100
Advanced Sensor Technology Massachusetts 100
Orion Research Limited United Kingdom 100
Orion Research Puerto Rico, Inc. Delaware 100
Russell pH Limited Scotland 100
Rutter & Co. Netherlands 100
Rutter Instrumentation S.A.R.L. France 90
Systech B.V. Netherlands 50
ThermedeTec Corporation Delaware 100
Thermedics Detection de Argentina S.A. Argentina 100
(1% of which shares are owned
directly by Thermedics Detection Inc.)
Thermedics Detection de Mexico, S.A. de C.V. Mexico 100
Thermedics Detection GmbH Germany 100
Thermedics Detection Limited United Kingdom 100
Thermedics Detection Scandinavia AS Norway 100

Thermo Sentron Inc. Delaware 74.25**
(additionally, 12.00%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
Allen Coding Systems Limited United Kingdom 100
Allen Coding Corporation Delaware 100
Goring Kerr Limited United Kingdom 100
Best Checkweighers Limited United Kingdom 100
Intertest (UK) Limited United Kingdom 100
Goring Kerr Detection Limited United Kingdom 100
Graseby Goring Kerr (NZ) Limited New Zealand 100
Graseby Goring Kerr Canada Inc. Ontario 100
Graseby Product Monitoring GmbH Germany 100
Goring Kerr Inc. New York 100
Ramsey France S.A.R.L. France 100
Ramsey Ingenieros S.A. Spain 100
Ramsey Italia S.R.L. Italy 100
Tecno Europa Elettromeccanica S.R.L. Italy 100
Ramsey Technology Inc. Massachusetts 100
Xuzhou Ramsey Technology Development Co., Limited China 50*
Thermo Sentron Australia Pty. Ltd.. Australia 100
Thermo Sentron B.V. Netherlands 100
Thermo Sentron Canada Inc. Canada 100
Thermo Sentron GmbH Germany 100
Thermo Sentron Limited United Kingdom 100
Hitech Electrocontrols Limited United Kingdom 100
Hitech Licenses Ltd. United Kingdom 100
Hitech Metal Detectors Ltd. United Kingdom 100
Westerland Engineering Ltd. United Kingdom 100
Thermo Sentron SEC Corporation Massachusetts l00
Thermo Sentron (South Africa) Pty. Ltd. South Africa 100
TMD Securities Corporation Massachusetts 100
Thermo Cardiosystems Inc. Massachusetts 60.05**
(additionally, 0.21%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
International Technidyne Corporation Delaware 100
International Technidyne Corporation Limited United Kingdom 100
Nimbus Inc. Massachusetts 100
TCA Securities Corporation Massachusetts 100
Thermo Voltek Corp. Delaware 66.45**
(additionally, 2.74%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
Thermo Voltek Europe B.V. Netherlands 100
Comtest Instrumentation, B.V. Netherlands 100
Comtest Italia S.R.L. Italy 100
Comtest Limited United Kingdom 100
Milmega Limited United Kingdom 100
TVL Securities Corporation Delaware 100
UVC Realty Corp. New York 100
Thermo Administrative Services Corporation Delaware 100

Thermo Amex Management Company Inc. Delaware 100
Thermo Amex Finance, L.P. Delaware 99*
Thermo Amex Convertible Growth Fund I., L.P. Delaware 99*
Thermo Ecotek Corporation Delaware 93.77**
Central Valley Fuels Management Inc. Delaware 100
Delano Energy Company Inc. Delaware 100
Eco Fuels Inc. Wyoming 100
EuroEnergy Group, B.V. Italy 50*
Independent Power Services Corporation Nevada 100
KFP Operating Company, Inc. Delaware 100
Lake Worth Generation LLC Delaware 100
Mountainview Power Company Delaware 100
Riverside Canal Power Company California 100
SFS Corporation New Hampshire 100
Star/RESC LLC Texas 75
TCK Fuels Inc. Delaware 100
KFx Fuel Partners, L.P. Delaware 95*
(2% of which is owned
directly by Eco Fuels Inc.)
TES Securities Corporation Delaware 100
Thermendota, Inc. California 100
Mendota Biomass Power, Ltd. California 100
MBPL Agriwaste Corporation California 100
Thermo Ecotek International Holdings Inc. Cayman Islands 100
Thermo Ecotek Europe Holdings B.V. Netherlands 100
EMD Ventures B.V. Netherlands 65*
ECS sro Czech Republic 50*
EMD Pribram sro Czech Republic 50*
EuroEnergy Group B.V. Netherlands 50*
Thermo EuroVentures sro Czech Republic 100
Thermo Ecotek International Inc. Cayman Islands 100
TCK Cogeneration Dominicana Inc. Cayman Islands 100
(1% of which shares are owned directly by Thermo Ecotek International
Holdings Inc.)
TCK Dominicana Holdings Inc. Cayman Islands 100
(1% of which shares are owned directly by
Thermo Ecotek International Holdings Inc.)
Thermo Electron of Maine, Inc. Maine 100
Gorbell/Thermo Electron Power Company Maine 80*
Thermo Electron of New Hampshire, Inc. New Hampshire 100
Hemphill Power and Light Company New Hampshire 66*
Thermo Electron of Whitefield, Inc. New Hampshire 100
Whitefield Power and Light Company New Hampshire 100*
(39% of which is owned
directly by SFS Corporation)
Star Natural Gas Company Delaware 95
Thermo Fuels Company, Inc. California 100
Thermo Trilogy Corporation Delaware 80.03**
Thermo Trilogy International Holdings, Inc. Cayman Islands 100

AgriSense-BCS, Ltd. United Kingdom 100
P J Margo Pvt. Ltd. India 50*
Ulna Incorporated California 100
Woodland Biomass Power, Inc. California 100
Woodland Biomass Power, Ltd. California 100*
(.1% of which is owned directly
by Thermo Ecotek Corporation)
Thermo Electron Foundation, Inc. Massachusetts 100
Thermo Electron Metallurgical Services, Inc. Texas 100
Thermo Finance Company B.V. Netherlands 100
Thermo Fibertek Inc. Delaware 91.34**
AES Equipos y Sistemas S.A. de C.V. Mexico 100
Fibertek Construction Company, Inc. Maine 100
Thermo AES Canada Inc. Canada 100
Thermo Black Clawson Inc. Delaware 100
Thermo Black Clawson (China) China 100
Thermo Black Clawson S.A. France 100
Thermo Fibertek Holdings Limited United Kingdom 100
Thermo Black Clawson Limited United Kingdom 100
Thermo Fibertek U.K. Limited United Kingdom 100
Vickerys Holdings Limited United Kingdom 100
Vickerys Limited United Kingdom 100
Winterburn Limited United Kingdom 100
Thermo Web Systems, Inc. Massachusetts 100
Fiberprep Inc. Delaware 95
(31.05% of which shares are owned
directly by E. & M. Lamort, S.A.)
Fiberprep Securities Corporation Delaware 100
Thermo Fibergen Inc. Delaware 70.81**
(additionally, 1.81%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
Fibergen Securities Corporation Massachusetts 100
GranTek Inc. Wisconsin 100
TMO Lamort Holdings Inc. Delaware 100
E. & M. Lamort, S.A. France 100
Lamort Black-Clawson Industrial Ltda. Brazil 70
Lamort GmbH Germany 100
Lamort Iberia S.A. Spain 100
Lamort Italia S.R.L. Italy 100
Lamort Paper Services Ltd. United Kingdom 100
Nordiska Lamort Lodding AB Sweden 100
Thermo Instrument Systems Inc. Delaware 85.40**
Analytical Instrument Development, Inc. Pennsylvania 100
Eberline Instrument Company Limited United Kingdom 100
Eberline Instrument Corporation New Mexico 100
Epsilon Industrial Inc. Texas 100
ESM Eberline Instruments Strahlen - und Umweltmesstechnik Germany 100
GmbH

Fisons Instruments Vertriebs GmbH Germany 100
Gas Tech Inc. California 100
Gas Tech Australia, Pty. Ltd. Australia 50*
Gas Tech Partnership California 50*
Gastech Instruments Canada Ltd. Canada 100
Life Sciences International Limited United Kingdom 100
Comdata Services Limited England 100
Lipshaw Limited England 100
Luckham Limited England 100
Phicom Limited England 100
Shandon Scientific Limited England 100
Southions Investments Limited England 100
Sungei Puntar Rubber Estate Limited England 100
Westions Limited England 100
Whale Scientific Limited England 100
Helmet Securities Limited England 100
Life Sciences International GmbH Germany 100
Life Sciences International Kft Hungary 100
Life Sciences International, Inc. Pennsylvania 100
LSI (US) Inc. Delaware 100
LSI North America Service Inc. Delaware 100
Life Sciences International Holdings BV Netherlands 100
Life Sciences International (Poland) SP z O.O Poland 100
Angila Scientific Instruments Limited England 100
Britlowes Limited England 100
Commendstar Limited England 100
Consumer & Video Holdings Limited England 100
Video Communications Limited England 100
Greensecure Projects Limited England 100
Labsystems Europe GA Spain 100
Labsystems Ges mbH Austria 100
Omnigene Limited England 58.50
Shandon Southern Instruments Limited England 100
Shenbridge Limited England 100
Southern Instruments Holdings Limited England 100
Metrika Systems Corporation Delaware 67.49**
(additionally, 8.11%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
Radiometrie RM GmbH Germany 100
Eberline Radiometrie S.A. France 100
Gamma-Metrics California 100
MF Physics Corporation Delaware 100
Radiometrie Corporation Delaware 100
DMC Mess & Regeltechnik GmbH Germany 100
Radiometrie U.S.A., Inc. California 100
Radiometrie Limited United Kingdom 100
National Nuclear Corporation California 100

Thermo Nucleonics LLC Delaware 51
(additionally, 49% of the shares are owned
directly by TBA Nucleonics Holding Corporation)
ONIX Systems Inc. Delaware 80.31**
(additionally, 0.73%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
Brandt Instruments, Inc. Delaware 100
CAC Inc. Delaware 100
Flow Automation Inc. Texas 100
Lots 82 and 83, Inc. Louisiana 100
Mid-South Power Systems, Inc. Louisiana 100
Mid-South Controls & Services, Inc. Louisiana 100
Thermo Instrument Controls de Mexico, S.A. de C.V. Mexico 100
(1% of which shares are owned directly
by ONIX Systems Inc.)
ONIX Process Analysis Inc. Texas 100
OnIX Holdings Limited England 100
CAC UK Limited England and Wales 100
ONIX Measurement Limited England and Wales 100
Peek Environmental Limited England and Wales 100
Sarasota Data Products Limited England and Wales 100
Sarasota Instrumentation Limited England and Wales 100
VG Gas Analysis Limited England and Wales 100
Polysonics, Inc. Texas 100
TN Spectrace Europe B.V. Netherlands 100
TN Technologies Inc. Texas 100
Kay-Ray/Sensall, Inc. Delaware 100
TN Technologies Canada Inc. Canada 100
Westronics Inc. Texas 100
Optek-Nicolet Holdings Inc. Wisconsin 100
Thermo Optek Corporation Delaware 92.70**
(additionally, 2.01%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
Diametrix Detectors, Inc. Delaware 100
FI Instruments Inc. Delaware 100
Gebrueder Haake GmbH Germany 100
RHEO S.A. France 100
SWO Polymertechnik GmbH Germany 100
HB Instruments Inc. Delaware 100
Scintag, Inc. California 100
Spectronic Instruments, Inc. Delaware 100
SLM International Inc. Illinois 100
Thermo Jarrell Ash Corporation Massachusetts 100
A.R.L. Applied Research Laboratories S.A. Switzerland 100
Fisons Instruments (Proprietary) Limited South Africa 100
Thermo Optek Wissenschaftliche Gerate GesmbH Austria 100
Baird De Brazil Representacoes Ltda. Brazil 100

Beijing Baird Analytical Instrument Technology China 100
Co. Limited
Cahn Instrument Corporation Wisconsin 100
Mattson Instruments Limited United Kingdom 100
Thermo Optek Limited United Kingdom 100
Norlab Instrument of Aberdeen (UK) United Kingdom 100
Thermo Elemental Limited United Kingdom 100
Unicam Limited United Kingdom 100
Unicam Export Limited United Kingdom 100
Unicam Analytical Technology Netherlands B.V. Netherlands 100
Unicam Italia SpA Italy 100
Unicam S.A. Belgium 100
Thermo Optek Nordic AB Sweden 100
Nicolet Instrument Corporation Wisconsin 100
Nicolet Japan K.K. Japan 100
Spectra-Tech, Inc. Wisconsin 100
Spectra-Tech, Europe Limited United Kingdom 100
Nicolet Instrument GmbH Germany 100
Optek Securities Corporation Massachusetts 100
Planweld Holding Limited United Kingdom 100
Nicolet Instrument Limited United Kingdom 100
Hilger Analytical Limited United Kingdom 100
Thermo Electron Limited United Kingdom 100
Thermo Instrument Systems Japan Holdings, Inc. Delaware 100
Nippon Jarrell-Ash Company, Ltd. Japan 100
Thermo Instruments (Canada) Inc. Canada 100
Fisons Instruments Inc. Canada 100
Unicam Analytical Inc. Canada 100
Thermo Optek France S.A. France 100
Thermo Optek Holding B.V. Netherlands 100
Baird Europe B.V. Netherlands 100
Baird France S.A.R.L. France 100
VG Systems Limited United Kingdom 100
VG Elemental Limited United Kingdom 100
Thermo Group B.V. Netherlands 100
Thermo Optek Materials Analysis (S.E.A.) Pte Limited Singapore 100
ThermoSpectra Corporation Delaware 82.45**
(additionally, 9.73%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
Gould Instrument Systems, Inc. Ohio 100
Kevex Instruments Inc. Delaware 100
Kevex X-Ray Inc. Delaware 100
Neslab Instruments Europa BV Netherlands 100
Neslab Instruments, Inc. New Hampshire 100
Neslab Instruments Limited England 100
Nicolet Instrument Technologies Inc. Wisconsin 100
NORAN Instruments Inc. Wisconsin 100
ThermoMicroscopes Corp. California 100
ThermoMicroscopes S.A. Switzerland 100

PSI Virgin Islands Incorporated U.S. Virgin Islands 100
Sierra Research and Technology, Inc. Delaware 100
ThermoSpectra B.V. Netherlands 100
Nicolet Technologies B.V. Netherlands 100
Bakker Electronics Limited United Kingdom 100
NORAN Instruments B.V. Netherlands 100
ThermoSpectra GmbH Germany 100
Gould Nicolet Messtechnik GmbH Germany 100
NORAN Instruments GmbH Germany 100
ThermoMicroscopes GmbH Germany 100
ThermoSpectra Limited United Kingdom 100
Nicolet Technologies Ltd. United Kingdom 100
ThermoSpectra S.A. France 100
Nicolet Technologies S.A.R.L. France 100
Spectrace Instruments Inc. California 100
TMO THI Acquisition Corp. Delaware 100
Thermo Electron Sweden Forvaltning AB Sweden 100
Quest-Finnigan Holdings Inc. Virginia 100
Quest-TSP Holdings Inc. Delaware 100
ThermoQuest Corporation Delaware 89.31**
(43.9%** of which shares are owned
directly by Quest-Finnigan Holdings Inc.)
(additionally, 0.31% of the shares are owned directly by The Thermo
Electron Companies Inc.)
Denley Instruments Limited England 100
E-C Apparatus Limited England 100
Finnigan FT/MS Inc. Delaware 100
Finnigan Corporation Delaware 100
Finnigan Instruments, Inc. New York 100
Finnigan International Sales, Inc. California 100
Finnigan MAT China, Inc. California 100
Finnigan MAT (Delaware), Inc. Delaware 100
Finnigan MAT Instruments, Inc. Nevada 100
Finnigan MAT International Sales, Inc. California 100
Finnigan MAT (Nevada), Inc. Nevada 100
Finnigan MAT GmbH Germany 100
ThermoQuest Analytische Systeme GmbH Germany 100
Finnigan MAT S.R.L. Italy 100
Thermo Separation Products S.R.L. Italy 100
Masslab Limited United Kingdom 100
Thermo Instruments Australia Pty. Limited Australia 100
ThermoQuest Ltd. United Kingdom 100
Finnigan MAT Ltd. United Kingdom 100
ThermoQuest AB Sweden 100
Thermo Separation Products Ltd. United Kingdom 100
Finnigan Properties, Inc. California 100
Forma Scientific, Inc. Delaware 100
Forma Ohio Inc. Ohio 100
International Equipment Company Delaware 100

International Equipment Company Limited England 100
Savant Instruments, Inc. New York 100
Forma Scientific Limited England 100
Hypersil Inc. Delaware 100
Hypersil Limited England 100
Life Sciences International (Hong Kong) Limited Hong Kong 100
Life Sciences International, Inc. Pennsylvania 100
Life Sciences (Europe) Limited England 100
Life Sciences International (UK) Limited England 100
Kenbury Limited England 100
Savant Instruments Limited England 100
ThermoQuest B.V. Netherlands 100
Thermo Separation Products B.V. Netherlands 100
Thermo Separation Products B.V. B.A. Belgium 100
ThermoQuest France S.A. France 100
Finnigan Automass S.A. France 100
Finnigan MAT S.A.R.L. France 100
Thermo Separation Products S.A. France 100
ThermoQuest Italia S.p.A. Italy 100
ThermoQuest Spain S.A. Spain 100
ThermoQuest Wissenschaftliche Gerate GmbH Austria 100
Thermo Separation Products AG Switzerland 100
Thermo Separation Products Inc. Delaware 100
ThermoQuest K.K. Japan 100
RealFlex Systems Inc. Texas 100
SID Instruments Inc. Delaware 100
FI S.A. France 100
Fisons Instruments BV Netherlands 100
Fisons Instruments NV Belgium 100
Fisons Instruments K.K. Japan 100
NK Instruments Inc. Delaware 100
Thermo Capillary Electrophoresis Inc. Delaware 100
Thermo Haake Ltd. United Kingdom 100
Thermo Haake (U.K.) Limited United Kingdom 100
Thermo Instrumentos Cientificos S.A. Spain 100
Tera Systemes
Thermo BioAnalysis Corporation Delaware 61.98**
(4.1%** of which shares are owned directly by
Quest-TSP Holdings Inc. and 1.8% of which shares
are owned directly by Quest-Finnigan Holdings Inc.
Additionally, 21.75%** of the shares are owned directly by
The Thermo Electron Companies Inc.)
BioStar, Inc. Delaware 100
Data Medical Associates, Inc. Texas 100
DMA Latinoamerica S.A. de C.V. Mexico 50
Denley Instruments Inc. North Carolina 100
Fastighets AB Skrubba Sweden 100
Dynex Technologies spol. s.r.o. Czech Republic 100
DYNEX Technologies (Asia) Inc. Delaware 100

DYNEX Technologies Inc. Virginia 100
DYNEX Technologies GmbH Germany 100
Hybaid Limited England 100
Hybaid BV Netherlands 100
Thermo Labsystems B.V. Netherlands 100
Labsystems Inc. Delaware 100
Thermo BioAnalysis Japan K.K. Japan 100
Labsystems OY Finland 100
Biosystems OY Finland 100
Labsystems (Hong Kong) Limited Hong Kong 99
Life Sciences International (Hong Kong) Limited Hong Kong 99
Labsystems BTD China 32.50
Labsystems LHD China 100
Labsystems Lenpipette Russia 95
Labsystems Pakistan (Private) Ltd Pakistan 33.50
Labsystems Sweden AB Sweden 100
Labsystems (UK) Limited England 100
Life Sciences International SNC France 100
Shandon SA France 100
Shandon (France) SA France 100
Shandon Scientific Limited United Kingdom 100
Anglia Scientific Instruments Limited United Kingdom 100
Shandon Southern Instruments Limited United Kingdom 100
Life Sciences International (Benelux) B.V. Netherlands 100
Shandon Inc. Pennsylvania 100
E-C Apparatus Corporation Florida 100
Whale Scientific Corporation Colorado 100
ALKO Diagnostic Corporation Massachusetts 100
TBA Nucleonics Holding Corporation Delaware 100
Thermo Nucleonics LLC Delaware 49
TBA Securities Corporation Massachusetts 100
Shandon GmbH Germany 100
Thermo BioAnalysis GmbH Germany 100
Hybaid GmbH Germany 100
Angewandte Gentechnologie Systems GmbH Germany 100
Labsystems GmbH Germany 100
Thermo LabSystems Vertriebs GmbH Germany 100
Thermo BioAnalysis (Guernsey) Ltd. Channel Islands 100
Thermo BioAnalysis Holdings, Limited United Kingdom 100
Thermo Fast U.K. Limited United Kingdom 100
Dynex Technologies Limited United Kingdom 100
Thermo BioAnalysis Limited United Kingdom 100
Thermo LabSystems Limited United Kingdom 100
Thermo BioAnalysis S.A. France 100
Thermo LabSystems S.A.R.L. France 100
Labsystems S.A.R.L. France 100
Thermo LabSystems (Australia) Pty Limited Australia 100
Thermo LabSystems Inc. Massachusetts 100
BioAnalysis LabSystems, S.A. Spain 100
Trace Scientific Limited Australia 100

Trace BioSciences Ltd. Australia 100
Trace BioSciences NZ Limited New Zealand 99
Trace America, Inc. Florida 100
Herbos Dijaganosticka Croatia 50
Shanghai Long March Chiron Trace Medical Science Co. China 22
Ltd.
Thermo Environmental Instruments Inc. California 100
Andersen Instruments Inc. Delaware 100
Andersen Instruments Limited United Kingdom 100
MIE Corporation Massachusetts 100
Thermo Instruments do Brasil Ltda. Brazil 100
(1% of which shares are owned directly
by Thermo Jarrell Ash Corporation)
Van Hengel Holding B.V. Netherlands 100
Thermo Instrument Systems B.V. Netherlands 100
Euroglas B.V. Netherlands 100
Mesure de Traces Netherlands 100
ThIS Automation B.V. Netherlands 100
This Analytical B.V. Netherlands 100
This Gas Analysis B.V. Netherlands
This Lab Systems B.V. Netherlands 100
This Scientific B.V. Netherlands 100
Thermo Instruments GmbH Germany 100
Thermo Jarrell Ash, S.A. Spain 100
Thermo Vision Corporation Delaware 78.27**
(additionally, 1.27%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
CID Technologies Inc. New York 100
Centro Vision Inc. Delaware 100
Hilger Crystals Limited United Kingdom 100
Laser Science, Inc. Delaware 100
Oriel Instruments Corporation Delaware 100
Thermo Vision Opticon Corporation Delaware 100
Thermo Power Corporation Massachusetts 78.62**
NuTemp, Inc. Illinois 100
Peek Limited Scotland 100
Peek Data Limited England 100
Peek Group Services Limited England 100
Dubilier Warminster Limited England 100
International Resistance Co Limited England 100
Minicircuits Limited England 100
Peek International Limited England 100
Peek Corporation Delaware 100
Peek Traffic Inc. Delaware 100
Peek Traffic Systems Inc. Florida 100
Saratec Measurement Inc. Florida 100
Signal Control Company Delaware 100
Signal Maintenance, Inc. Delaware 100
StreeterAmet Inc. Delaware 100
Peek Traffic USA Inc. Florida 100
Peek Traffic GmbH Germany 100

Peek International B.V. Netherlands 100
Peek Projects BV Netherlands 100
Peek Promet doo Croatia 100
Peek Traffic A.B. Sweden 100
Peek Trafikk AS Norway 100
Peek Parking Systems AB Sweden 100
Peek Trafik a-s Denmark 100
Peek Traffic B.V. Netherlands 100
Peek Limited Hong Kong 100
Peek Trafikk Sendirian Bermad Malaysia 100
Peek Traffic (Thailand) Limited Thailand 100
Sichuan Modern Control System Engineering
Company Limited China 41*
Peek Traffic OY Finland 100
Peek Investments, Limited England 100
Dubilier America, Inc. Delaware 100
Automatic Connector Inc. New York 100
Peek Systems Limited England 100
Sotwell Limited England 100
Peek Technology Limited England 100
Peek Traffic Limited England 100
GK Instruments Limited England 100
Sarasota Traffic Limited England 100
Streeteramet Limited England 100
Weighwrite Limited England 100
Radley Services Limited England 100
Atest Electronics Limited England 100
Bartsign Limited England 100
Greenpar Holdings Limited England 100
Helvetia Automatic Products Limited England 100
Peek Field Services Limited England 100
Peek Traffic Systems B.V. Netherlands 100
Radley (1) Limited England 100
Smartways Limited England 100
Tollstar Limited England 100
Takepine Limited United Kingdom 100
Tecogen Securities Corporation Massachusetts 100
ThermoLyte Corporation Delaware 98**
Optronics, Inc. Oklahoma 100
Thermo TerraTech Inc. Delaware 85.95**
Holcroft (Canada) Limited Canada 100
Holcroft Corporation Delaware 100
Holcroft GmbH Germany 100
Metallurgical, Inc. Minnesota 100
Cal-Doran Metallurgical Services, Inc. California 100
Metal Treating Inc. Wisconsin 100
Normandeau Associates, Inc. New Hampshire 100
TMA/Hanford, Inc. Washington 100

The Randers Killam Group Inc. Delaware 94.81**
(additionally, 0.99%** of the shares are owned
directly by Thermo Electron Corporation)
Clark-Trombley Consulting Engineers, Inc. Michigan 100
Randers Engineering, Inc. Michigan 100
Randers Engineering of Massachusetts, Inc. Michigan 100
Randers Group Property Corporation Michigan 100
Redeco Incorporated Michigan 100
Viridian Technology Incorporated Michigan 100
The Killam Group, Inc. Delaware 100
CarlanKillam Consulting Group, Inc. Florida 100
CarlanKillam Consulting Group of Alabama, Inc. Alabama 100
Thermo Consulting & Design Inc. Delaware 100
Engineering Technology and Knowledge Corporation Delaware 100
Elson T. Killam Associates, Inc. New Jersey 100
BAC Killam Inc. New York 100
N.H. Bettigole Co., Inc. Delaware 100
N.H. Bettigole P.A. New Jersey 100
N.H. Bettigole P.C. New York 100
CarlanKillam Construction Services, Inc. Florida 100
Duncan, Lagnese and Associates, Pennsylvania 100
Incorporated
E3-Killam, Inc. New York 100
Killam Associates, Inc. Ohio 100
Killam Management and Operational New Jersey 100
Services, Inc.
Fellows, Read & Associates, Inc. New Jersey 100
Killam Associates, New England Inc. Delaware 100
George A. Schock & Associates, Inc. New Jersey 100
Jennison Engineering, Inc. Vermont 100
Thermo Analytical Inc. Delaware 100
Skinner & Sherman, Inc. Massachusetts 100
Thermo EuroTech (Delaware) Inc. Delaware 77.83**
(additionally, 10.79% of the shares are owned
directly by The Thermo Electron Companies Inc.)
Thermo EuroTech N.V. Netherlands
Thermo EuroTech Ireland Ltd. Ireland 100
Green Sunrise Holdings Ltd. Ireland 70
AutoRod Ltd. Ireland 100
Green Sunrise Industries Ltd. Ireland 100
GreenStar Recycling Ltd. Ireland 100
Pipe & Drain Services Ltd. Ireland 100
GreenStar Products Ltd. Ireland 70
Grond- & Watersaneringstechniek Nederland B.V. Netherlands 100
Refining & Trading Holland B.V. Netherlands 100

ThermoRetec Corporation Delaware 69.12**
(additionally, 1.89%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
Benchmark Environmental Corporation New Mexico 100
Eberline Holdings Inc. Delaware 100
Eberline Analytical Corporation New Mexico 100
Thermo Hanford Inc. Delaware 100
TMA/NORCAL Inc. California 100
ThermoRetec Construction Corporation Virginia 100
ThermoRetec Resource Planning & Management Systems Connecticut 100
Corporation
ThermoRetec Consulting Corporation Delaware 100
GeoWest Golden Inc. Colorado 100
GeoWest TriTechnics of Ohio, LLC Colorado 100
Retec North Carolina, Inc. North Carolina 100
Retec Engineering P.C. New York 100
RETEC Thermal, Inc. Delaware 100
Thermo Fluids Inc. Delaware 100
TPS Technologies Inc. Florida 100
TPST Soil Recyclers of California Inc. California 100
California Hydrocarbon, Inc. Nevada 100
TPST Soil Recyclers of Maryland Inc. Maryland 100
Todds Lane Limited Partnership Maryland 100*
(1% of which is owned directly
by TPS Technologies Inc.)
TPST Soil Recyclers of New York Inc. New York 100
TPST Soil Recyclers of Oregon Inc. Oregon 100
TPST Soil Recyclers of South Carolina Inc. Delaware 100
TPST Soil Recyclers of Virginia Inc. Delaware 100
TPST Soil Recyclers of Washington Inc. Washington 100
TRI Oak Ridge Inc. Delaware 100
TRI Oak Ridge LLC Delaware 50
(additionally, 50% of the shares are owned
directly by Coleman Services Incorporated)
TRUtech L.L.C. Delaware 47.5*
Thermo Securities Corporation Delaware 100
Thermo Technology Ventures Inc. Idaho 100
Plasma Quench Investment Limited Partnership Delaware 60*
ThermoTrex Corporation Delaware 63.90**
ThermoLase Corporation Delaware 71.09**
(additionally, 8.47%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
Creative Beauty Innovations, Inc. Texas
100
The Greenhouse Spa, Inc. Pennsylvania 100
ThermoLase England L.L.C. Delaware 50*
ThermoLase UK Limited United Kingdom 100
ThermoLase France L.L.C. Delaware 71.05*
ThermoDess S.A.S. France 71.05*

ThermoLase International L.L.C. Delaware 35*
ThermoLase Japan L.L.C. Wyoming
50*
Thira Japan, Inc. Japan 100
ThermoTrex East Inc. Massachusetts 100
Trex Medical Corporation Delaware 70.20**
(additionally, 6.88%** of the shares are owned
directly by The Thermo Electron Companies Inc.)
Bennett X-Ray Corporation New York 100
Bennett International Corporation U.S. Virgin Islands 100
Eagle X-Ray, Inc. New York 100
Island X-Ray Incorporated New York 100
Continental X-Ray Corporation Delaware
100
Trex Medical France S.A. France 100
Societe Financiere Trophy S.A. France 100
Trophy Radiologie S.A. France 100
Stephan'X S.A. France 100
Trophy Benelux S.A. Belgium 100
Trophy Radiologie Italia S.R.L. Italy 100
Trophy Radiologie Japan Kabushiki Kaisha Japan 100
Trophy Radiologie GmbH (FRG) Germany 100
P.T. Trophy Rajawali Indonesia Indonesia 100
Trophy Radiologia Espana SL Spain 100
Trophy Rontgen Sanayi Anonim Sirketi Turkey 100
Trophy Radiologie U.K. Ltd. United Kingdom 100
Trex Trophy Dental Inc. Virginia 100
Ardet Italia S.R.L. Italy 100
SCI Boucher Debard Baudry Guillot France 100
XRE Corporation Delaware 100
Trex Communications Corporation Delaware 68.89**
CCS TrexCom, Inc. Georgia 100
Computer Communication Specialists UK Ltd United Kingdom 100
EMP TrexCom Inc. Delaware 100
LNR Communications, Inc. Delaware 100
TMO, Inc. Massachusetts 100
TMOI Inc. Delaware 100
Thermo Biomedical Inc. Delaware 100
Thermo Digital Technologies Corporation Delaware 100
Thermo Digital Technologies L.L.C. Delaware 100
Thermo Electron Export Inc. Barbados 100
(equally owned among TMO, TMD, TCA, TCK, TFT, THI, THP, TTT, TVL, TLZ, THS, TBA,
TOC, TMQ and TXM )
Thermo Electron (London) Ltd. United Kingdom 50*
Thermo Finance (UK) Limited United Kingdom 100
Thermo Foundation, Inc. Massachusetts 100
TMO THI Holdings Inc. Delaware 100
Thermo Leasing Corporation Delaware 100
Thermo Capital Company LLC Delaware 50

* Joint Venture/Partnership ** As of January 2, 1999