EXHIBIT 31.1

CERTIFICATION OF
CHIEF EXECUTIVE OFFICER

CERTIFICATION PURSUANT
TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Robert L. Demorest, certify that:

|1. |  | I
have reviewed this Quarterly Report on Form 10-Q of MOCON, Inc.;
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|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;
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|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 registrant as of, and
for, the periods presented in this report;
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|4. |  | The
registrant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 registrant and have:
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| | 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 registrant, 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;
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| | b) |  | Evaluated the
effectiveness of the registrant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
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| | c) |  | Disclosed in
this report any change in the registrants internal control over financial
reporting that occurred during the registrants most recent fiscal quarter
that has materially affected, or is reasonably likely to materially affect, the
registrants internal control over financial reporting; and
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|5. |  | The
registrants other certifying officer(s) and I have disclosed, based on our
most recent evaluation of internal control over financial reporting, to the
registrants auditors and the audit committee of registrants board of
directors (or persons performing the equivalent functions):
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| | 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 registrants ability to record, process, summarize and report financial
information; and
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| | b) |  | Any fraud,
whether or not material, that involves management or other employees who have a
significant role in the registrants internal control over financial
reporting.
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Date: May 17, 2004

/s/ Robert L. Demorest

Robert L. DemorestChief Executive
Officer and President(Principal Executive Officer)

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