NEWS RELEASE

For Immediate Release                         Contact:  Robert H. Hertz
                                                        Chief Financial Officer

                                                        Steve Cantor
                                                        Manager, Corp. Comm.
                                                        (617) 272-6100


                   DYNATECH SELLS MEDICAL AND DIAGNOSTIC UNIT

BURLINGTON,  Mass.,  February 5, 1996 . . . Dynatech Corporation (Nasdaq symbol:
DYTC) announced today that it signed an agreement to sell the assets of Dynatech
Laboratories  Worldwide  (DLW)  for  approximately  $43  million  in  cash.  The
purchaser is Thermo BioAnalysis, a subsidiary of Thermo Instrument Systems, Inc.
(Amex symbol: THI). Based in Chantilly, Virgina, Dynatech Laboratories Worldwide
manufactures  automated Microtiterr equipment and disposable plasticware used in
medical research and clinical  immunodiagnostic testing.

John F. Reno, president and chief executive officer, said: "The sale of Dynatech
Laboratories   Worldwide   reflects  our  strategic   focus  as  a  supplier  of
communication  technologies solutions. We are pleased that Thermo BioAnalysis is
offering employment to all DLW personnel.

"The sale provides  additional  financial  resources to fund our core businesses
that are leaders in  high-growth,  competitive  markets and to expand our market
position with highly focused acquisitions," said Reno.

Dynatech Corporation supplies products for the support of voice, video, and data
communications.  Headquartered in Burlington,  Massachusetts, Dynatech sells its
products worldwide through subsidiaries located throughout the Americas,  Europe
and Asia.