**EXHIBIT31.1**

 

CERTIFICATIONS PURSUANT TO RULE 13a-14(a)

 

I, John J. Sullivan, Ph.D., certify that:

 

1.                                       I have reviewedthis annual report on Form 10-K of Mesa Laboratories, Inc.;

2.                                       Based on myknowledge, this report does not contain any untrue statement of a material factor omit to state a material fact necessary to make the statements made, inlight of the circumstances under which such statements were made, notmisleading with respect to the period covered by this report;

3.                                       Based on myknowledge, the financial statements, and other financial information includedin this report, fairly present in all material respects the financialcondition, results of operations and cash flows of the small business issuer asof, and for, the periods presented in this report;

4.                                       The smallbusiness issuer’s other certifying officer(s) and I are responsible forestablishing and maintaining disclosure controls and procedures (as defined inExchange Act Rules 13a-15(e) and 15d-15(e)) and internal control overfinancial reporting (as defined in Exchange Act Rules 13a-15(f) and15d-15(f)) for the small business issuer and have:

(a)     Designed such disclosure controls and procedures, orcaused such disclosure controls and procedures to be designed under oursupervision, to ensure that material information relating to the small businessissuer, including its consolidated subsidiaries, is made known to us by otherswithin those entities, particularly during the period in which this report isbeing prepared;

(b)    Designed such internal control over financialreporting, or caused such internal control over financial reporting to bedesigned under our supervision, to provide reasonable assurance regarding thereliability of financial reporting and the preparation of financial statementsfor external purposes in accordance with generally accepted accountingprinciples;

(c)     Evaluated the effectiveness of the small businessissuer’s disclosure controls and procedures and presented in this report ourconclusions 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 smallbusiness issuer’s internal control over financial reporting that occurredduring the small business issuer’s fourth fiscal quarter that has materiallyaffected, or is reasonably likely to materially affect, the small businessissuer’s internal control over financial reporting; and

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

(a)     All significant deficiencies and material weaknessesin the design or operation of internal control over financial reporting whichare reasonably likely to adversely affect the small business issuer’s abilityto record, process, summarize and report financial information; and

(b)    Any fraud, whether or not material, that involvesmanagement or other employees who have a significant role in the small businessissuer’s internal control over financial reporting.

 

 
| Date:  | June 29, 2009 |                    | /s/John J. Sullivan, Ph.D. |
|--------|--------------------|-------------------------|----------------------------|
|   |               | John J. Sullivan, Ph.D. |
|   |               | Chief Executive Officer |

 

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