AMENDMENT NUMBER 2 AND CONSENT TO NOTE AND EQUITY PURCHASE AGREEMENT

Exhibit 10.2.3

AMENDMENT NUMBER 2 AND CONSENT
TO
NOTE AND EQUITY PURCHASE AGREEMENT

          SECOND AMENDMENT AND CONSENT, dated as of December 22, 2005 (this “ Agreement ”), to the Note and Equity Purchase Agreement, dated as of July 23, 2004, as amended (as the same may amended, supplemented or modified from time to time in accordance with its terms, the “ Note Purchase ·Agreement ”), by and among MGP INSTRUMENTS, INC., a Delaware corporation (“ Borrower ”), DOSIMETRY ACQUISITIONS (U.S.), INC., a Delaware corporation (“ Topco ”), as Guarantor, the securities purchasers that are now and hereafter at any time parties thereto (each a “Purchaser and collectively, “ Purchasers ”), and AMERICAN CAPITAL FINANCIAL SERVICES, INC., a Delaware corporation (“ ACFS ”), as agent for Purchasers (“ Agent ”). All capitalized terms used herein and not otherwise defined shall have the meanings assigned to such terms in the Note Purchase Agreement.

RECITALS:

          WHEREAS, Topco wishes to enter into the Master Restructuring Agreement and Plan of Merger (“ Restructuring Agreement ”), by and among Topco, Global Monitoring Systems, Inc. (“ GMS ”) and the other parties listed therein, in the manner set forth in the Restructuring Agreement, in the form attached hereto as Exhibit A , in order to effect a reorganization of the overall corporate structure of the Loan Parties; and

          WHEREAS, the Loan Parties have requested that the Purchasers Consent to the transactions involving Topco under the Restructuring Agreement and waive breach of any covenants violated thereby; and

          WHEREAS, it is a condition to the Agreement by the Agent that GMS enter into the Guaranty in the form attached hereto as Exhibit B , and that GMS enter into a Pledge and Security. Agreement in the form attached hereto as Exhibit C .

          NOW, THEREFORE, in consideration of the premises and the agreements, provisions and covenants herein contained, each Loan Party, each Purchaser and the Agent agrees as follows:

ARTICLE 1

CONSENT

          1.1 The Purchasers hereby consent to the transactions involving Topco under the Restructuring Agreement and hereby waive breach of any covenant in the Note Purchase Agreement violated as a result of such transaction.

ARTICLE 2

OMNIBUS AMENDMENT

          2.1 As part of the transactions to occur under the Restructuring Agreement, Topco will merger with and into Dosimetry Acquisitions (U.S,), LLC (“ Dosimetry LLC ”), with Dosimetry LLC continuing as the surviving Person (the “ Merger ”). As a result, references in the Note Purchase Agreement to Topco that assume or treat it as a corporation and references to its officers, directors and stockholders shall cease to be correct after completion of the Merger. Accordingly, the Agent, Purchaser and the Loan Parties intend that all such references in the Note Purchase Agreement and the other Purchase Documents shall instead be deemed to be references to Dosimetry LLC, as the surviving Person in the Merger and that all descriptions, requirements and obligations in the Note Purchase Agreement of Topco, its officers, directors and stockholders, shall be construed so as to give the Agent and the Purchasers the same rights and benefits under the Note Purchase Agreement as they currently have with respect to Topco. The Loan Parties agree that, at any time, promptly upon request of the Agent, they shall enter into any amendment requested by the Agent to clarify the applicability, scope and operations of any provisions of the Note Purchase Agreement or any other Purchase Document in a manner that comports with the provisions of this Section 2.1.

ARTICLE 3

AMENDMENT

          3.1 The Note Purchase Agreement is hereby amended as follows:

          (a) Article 7.1(i) is deleted in its entirety and replaced with the following:

          [reserved].

ARTICLE 4

CONDITIONS PRECEDENT

          The provisions set