Exhibit 5

                                    February 13, 1995



Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C. 20549

          Re:  Instrument Systems Corporation
               Registration Statement on Form S-8

Gentlemen:

          Reference is made to the filing by Instrument Systems Corporation (the
"Corporation") of a Registration Statement on Form S-8 with the Securities and
Exchange Commission pursuant to the provisions of the Securities Act of 1933, as
amended, covering the registration of 1,000,000 shares of the Corporation's
Common Stock, $.25 par value per share, in connection with the Corporation's
1995 Stock Option Plan (the "Plan").

          As counsel for the Corporation, we have examined its corporate 
records, including its Certificate of Incorporation, as amended, By-Laws, its 
corporate minutes, the form of its Common Stock certificate, the Plan, related 
documents under the Plan  and such other documents as we have deemed necessary 
or relevant under the circumstances.

          Based upon our examination, we are of the opinion that:

     1.   The Corporation is duly organized and validly existing under the laws
of the State of Delaware.

     2.   There have been reserved for issuance by the Board of Directors of the
Corporation 1,000,000 shares of its Common Stock, $.25 par value per share.  The
shares of the Corporation's Common Stock, when issued pursuant to the Plan, will
be validly authorized, legally issued, fully paid and non-assessable.

          We hereby consent to be named in the Registration Statement and in the
Prospectus which constitutes a part thereof as counsel of the Corporation, and
we hereby consent to the filing of this opinion as Exhibit 5 to the Registration
Statement.

                                    Very truly yours,



                                    BLAU, KRAMER, WACTLAR &
                                         LIEBERMAN, P.C.