<ARTICLE> 5 <LEGEND> THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THERMEDICS DETECTION INC.'S REPORT ON FORM 10-Q FOR THE PERIOD ENDED OCTOBER 3, 1998 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS. </LEGEND> <MULTIPLIER> 1,000 <PERIOD-TYPE> 9-MOS <FISCAL-YEAR-END> JAN-02-1999 <PERIOD-END> OCT-03-1998 <CASH> 33,814 <SECURITIES> 0 <RECEIVABLES> 17,007 <ALLOWANCES> 1,016 <INVENTORY> 16,871 <CURRENT-ASSETS> 72,987 <PP&E> 12,241 <DEPRECIATION> 7,834 <TOTAL-ASSETS> 133,610 <CURRENT-LIABILITIES> 17,602 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 1,932 <OTHER-SE> 114,076 <TOTAL-LIABILITY-AND-EQUITY> 133,610 <SALES> 57,942 <TOTAL-REVENUES> 71,234 <CGS> 25,881 <TOTAL-COSTS> 32,247 <OTHER-EXPENSES> 7,426 <LOSS-PROVISION> 201 <INTEREST-EXPENSE> 303 <INCOME-PRETAX> 11,491 <INCOME-TAX> 4,539 <INCOME-CONTINUING> 6,952 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 6,952 <EPS-PRIMARY> 0.36 <EPS-DILUTED> 0.36