<PAGE>



                                                                    EXHIBIT 31.2
                                  CERTIFICATION

I, Robert V. Condon, certify that:

2.   I have reviewed this quarterly report on Form 10-QSB of Merrimac
     Industries, Inc.;

2.   Based on my knowledge, this report does not contain any untrue statement of
     a material fact or omit to state a material fact necessary to make the
     statements made, in light of the circumstances under which such statements
     were made, not misleading with respect to the period covered by this
     report;

3.   Based on my knowledge, the financial statements, and other financial
     information included in this report, fairly present in all material
     respects the financial condition, results of operations and cash flows of
     the small business issuer as of, and for, the periods presented in this
     report;

4.   The small business issuer's other certifying officer(s) and I are
     responsible for establishing and maintaining disclosure controls and
     procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for
     the small business issuer and have:

         (a)   Designed such disclosure controls and procedures, or caused such
               disclosure controls and procedures to be designed under our
               supervision, to ensure that material information relating to the
               small business issuer, including its consolidated subsidiaries,
               is made known to us by others within those entities, particularly
               during the period in which this report is being prepared;

         (b)   [Omitted pursuant to SEC Release Nos. 33-8238 and 34-47986]

         (c)   Evaluated the effectiveness of the small business issuer's
               disclosure controls and procedures and presented in this report
               our conclusions about the effectiveness of the disclosure
               controls and procedures, as of the end of the period covered by
               this report based on such evaluation; and

         (d)   Disclosed in this report any change in the small business
               issuer's internal control over financial reporting that occurred
               during the small business issuer's most recent fiscal quarter
               that has materially affected, or is reasonably likely to
               materially affect, the small business issuer's internal control
               over financial reporting; and

5.   The small business issuer's other certifying officer(s) and I have
     disclosed, based on our most recent evaluation of internal control over
     financial reporting, to the small business issuer's auditors and the audit
     committee of the small business issuer's board of directors (or persons
     performing the equivalent functions):

         (a)   All significant deficiencies and material weaknesses in the
               design or operation of internal control over financial reporting
               which are reasonably likely to adversely affect the small
               business issuer's ability to record, process, summarize and
               report financial information; and

         (b)   Any fraud, whether or not material, that involves management or
               other employees who have a significant role in the small business
               issuer's internal control over financial reporting.


Date: May 17, 2004



/s/ Robert V. Condon
--------------------
Vice President, Finance and
Chief Financial Officer