EXHIBIT 31.2

CERTIFICATION PURSUANT TO RULE
      13a-14(a) OR 15d-14(a) OF THE SECURITIES EXCHANGE ACT OF1934, AS ADOPTED PURSUANT TO SECTION 302 OF
    THE SARBANES-OXLEY ACT OF 2002

I, Walter A. Shephard, certify that:

|1) | I have reviewed
          this quarterly report on Form 10-Q of Zygo Corporation;                                                                                                                                                                                                                                                                                                        
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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)) and internal control over financial
          reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f))
          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; b)            Designed
      such internal control over financial reporting, or caused such internal
      control over financial reporting to be designed under our supervision,
      to provide reasonable assurance regarding the reliability of financial
      reporting and the preparation of financial statements for external purposes
      in accordance with generally accepted accounting principles; c)            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 d)            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 (the registrants fourth fiscal quarter in the case
      of an annual report) that has materially affected, or is reasonably likely
      to materially affect, the registrants internal control over financial
      reporting; and


|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 the 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 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.


Date: February 9, 2009

s/ Walter A. Shephard  Walter A. Shephard  Vice President, Finance,  Chief Financial Officer, and Treasurer




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