EXHIBIT 10.1
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                   SECOND AMENDMENT TO CREDIT AGREEMENT

      This SECOND AMENDMENT TO CREDIT AGREEMENT (this "Agreement"), dated
as of March 25, 2006, is between LANDAUER, INC., a Delaware corporation
("Borrower"); HOMEBUYER'S PREFERRED, INC., an Illinois corporation
("Homebuyer's Preferred"), HEALTHY HOME AIR, INC., a Delaware corporation
("Healthy Home"), and LANDAUER INTERNATIONAL LLC, a Delaware limited
liability company ("Landauer International") (Homebuyer's Preferred,
Healthy Home and Landauer International sometimes hereinafter are referred
to as each "Guarantor" and collectively as the "Guarantors"); and LASALLE
BANK NATIONAL ASSOCIATION, a national banking association ("Bank").


                             R E C I T A L S:
                             ----------------

      A.    Borrower and Bank entered into that certain Credit Agreement
dated as of April 13, 2004 (the "Original Credit Agreement"), as amended by
that certain First Amendment to Credit Agreement dated as of March 25, 2005
(the "First Amendment") between Borrower and Bank (the Original Credit
Agreement, as amended by the First Amendment, hereinafter is referred to as
the "Credit Agreement"), pursuant and subject to the terms and conditions
of which Bank agreed to make loans and other financial accommodations to
Borrower.

      B.    Each Guarantor is a Subsidiary of Borrower.  Each Guarantor
guaranteed Borrower's Obligations pursuant to that certain Guaranty dated
as of April 13, 2004 made by Guarantors in favor of Bank.  Each Guarantor
ratified and confirmed its obligations under the Guaranty pursuant to the
First Amendment.

      C.    Borrower and Guarantors have requested that Bank (i) extend the
Maturity Date to March 25, 2007 and (ii) increase the minimum tangible net
worth covenant to $22,400,000.

      D.    Bank is willing to agree to the requests of Borrower and
Guarantors on the terms and conditions set forth herein.

      NOW, THEREFORE, in consideration of the mutual agreements contained
herein, and for other good and valuable consideration, the receipt and
sufficiency of which hereby are acknowledged, Borrower, Guarantors and Bank
agree as follows:

      1.    INCORPORATION OF RECITALS.  The Recitals set forth above are
incorporated herein, are acknowledged by Borrower and Guarantors to be true
and correct and by this reference are made a part hereof.

      2.    DEFINITIONS.  All capitalized terms used but not elsewhere
defined herein shall have the respective meanings ascribed to such terms in
the Credit Agreement, as amended by this Agreement.

      3.    AMENDMENTS TO CREDIT AGREEMENT.  The Credit Agreement is
amended as set forth below:

            (a)   SECTION 1.1 - AMENDED DEFINITION.  Section 1.1 of the
      Credit Agreement is amended by deleting the current version of the
      definition of "Maturity Date" in its entirety and substituting the
      following version in lieu thereof:

                  "Maturity Date:  means the earlier of (i) March 27, 2007
            or (ii) the date on which Borrower's Obligations are
            accelerated pursuant to this Credit Agreement."



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            (b)   SECTION 6.10 - MINIMUM TANGIBLE NET WORTH.  Section 6.10
      of the Credit Agreement is deleted in its entirety and the following
      is substituted in lieu thereof:

                  "6.10 MINIMUM TANGIBLE NET WORTH.  Borrower shall not
            permit Tangible Net Worth to be less than $22,400,000 at the
            end of any Fiscal Quarter."

      4.    CONDITIONS TO EFFECTIVENESS.  The effectiveness of this
Agreement shall be subject to the satisfaction of all of the following
conditions in a manner, form and substance satisfactory to Bank:

            (a)   DELIVERY OF DOCUMENTS.  The following shall have been
      delivered to Bank, each duly authorized and executed and each in form
      and substance satisfactory to Bank:

                  (1)   this Agreement; and

                  (2)   such other instruments, documents, certificates,
            consents, waivers and opinions as Bank reasonably may request.

            (b)   NO DEFAULT.  No Event of Default or Incipient Default
      shall exist.

            (c)   MATERIAL ADVERSE EFFECT.  No event shall have occurred
      since December 31, 2005 which has had or could have a material
      adverse effect on the financial condition or affairs of Borrower.

      The date on which all of the conditions set forth in this Section 4
have been satisfied is referred to herein as the "Effective Date."

      5.    REFERENCES.  From and after the Effective Date, all terms used
in the Credit Documents which are defined in the Credit Agreement shall be
deemed to refer to such terms as amended by this Agreement.  This Agreement
shall constitute a "Credit Document."

      6.    REPRESENTATIONS AND WARRANTIES.  Borrower and each Guarantor
hereby confirms to Bank that the representations and warranties set forth
in the Credit Documents are true and correct in all material respects as of
the date hereof (unless any such representation or warranty relates to a
specific date, in which case such representation or warranty is true and
correct as of such date), and shall be deemed to be remade as of the date
hereof (unless any such representation or warranty relates to a specific
date, in which case such representation or warranty shall be deemed to be
remade as of such date).  Borrower and each Guarantor represents and
warrants to Bank that (i) it has full power and authority to execute and
deliver this Agreement and to perform its obligations hereunder, (ii) upon
the execution and delivery hereof, this Agreement will be valid, binding
and enforceable upon it in accordance with its terms (except as such
enforceability may be limited by (x) applicable bankruptcy, insolvency,
reorganization, moratorium or similar laws now or hereafter in effect
affecting the enforcement of creditors' rights generally and (y) equitable
principles (whether or not any action to enforce this Agreement is brought
at law or in equity), (iii) the execution and delivery of this Agreement
does not and will not contravene, conflict with, violate or constitute a
default under (A) its articles or certificate of incorporation, by-laws,
certificate of formation or operating agreement, as applicable, or (B) any
applicable law, rule, regulation, judgment, decree or order or any
agreement, indenture or instrument to which it is a party or is bound or
which is binding upon or applicable to all or any portion of its Property
and (iv) as of the date hereof no Event of Default exists.









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      7.    NO FURTHER AMENDMENTS; RATIFICATION OF LIABILITY.  Except as
amended hereby, the Credit Agreement and each of the other Credit Documents
shall remain in full force and effect in accordance with their respective
terms.  Borrower and each Guarantor hereby ratifies and confirms its
liabilities, obligations and agreements under the Credit Agreement and the
other Credit Documents, all as amended by this Agreement, and the Liens
created thereby, and acknowledges that (i) it has no defenses, claims or
set-offs to the enforcement by Bank of such liabilities, obligations and
agreements, (ii) Bank has fully performed all obligations to Borrower and
Guarantors which it may have had or has on and as of the date hereof and
(iii) other than as specifically set forth herein, Bank does not waive,
diminish or limit any term or condition contained in the Credit Agreement
or the other Credit Documents.  The Credit Documents, as amended by this
Agreement, contain the entire agreement between Bank, Borrower and
Guarantors with respect to the transactions contemplated hereby.

      8.    RELEASE OF CLAIMS.  In consideration of the execution and
delivery of this Agreement by Bank, the sufficiency of which is
acknowledged, and excepting only the contractual obligations respecting
future performance by Bank arising under the Credit Agreement and the other
Credit Documents, Borrower and each Guarantor hereby irrevocably releases
and forever discharges Bank and each of its affiliates, subsidiaries,
successors, assigns, directors, officers, employees, agents,
representatives and attorneys (each, a "Released Person") of and from all
damages, losses, claims, demands, liabilities, obligations, actions and
causes of action whatsoever which Borrower or such Guarantor may now have
or claim to have on and as of the date hereof against any Released Person,
whether presently known or unknown, liquidated or unliquidated, suspected
or unsuspected, contingent or non-contingent, and of every nature and
extent whatsoever (collectively, "Claims").  Borrower and each Guarantor
represents and warrants to Bank that it has not granted or purported to
grant to any other Person any interest whatsoever in any Claim, as security
or otherwise.  Borrower and each Guarantor shall indemnify, defend and hold
harmless each Released Person from and against any and all Claims and any
loss, cost, liability, damage or expense (including reasonable attorneys'
fees and expenses) incurred by any Released Person in investigating,
preparing for, defending against, providing evidence or producing documents
in connection with or taking other action in respect of any commenced or
threatened Claim.

      9.    COUNTERPARTS.  This Agreement may be executed in one or more
counterparts, each of which shall be deemed an original, and all of which,
when taken together, shall constitute one and the same instrument.

      10.   FURTHER ASSURANCES.  Borrower and each Guarantor covenants and
agrees that it will at any time and from time to time do, execute,
acknowledge and deliver, or will cause to be done, executed, acknowledged
and delivered, all such further acts, documents and instruments as
reasonably may be required by Bank in order to effectuate fully the intent
of this Agreement.

      11.   SEVERABILITY.  If any term or provision of this Agreement or
the application thereof to any party or circumstance shall be held to be
invalid, illegal or unenforceable in any respect by a court of competent
jurisdiction, the validity, legality and enforceability of the remaining
terms and provisions of this Agreement shall not in any way be affected or
impaired thereby, and the affected term or provision shall be modified to
the minimum extent permitted by law so as most fully to achieve the
intention of this Agreement.

      12.   CAPTIONS.  The captions in this Agreement are inserted for
convenience of reference only and in no way define, describe or limit the
scope or intent of this Agreement or any of the provisions hereof.

      13.   ENTIRE AGREEMENT.  This Agreement, the Credit Agreement and the
other Credit Documents executed prior or pursuant hereto constitute the
entire agreement among the parties hereto with respect to the transactions
contemplated hereby or thereby and supersede any prior agreements, whether
written or oral, relating to the subject matter hereof.

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      14.   APPLICABLE LAW.  THIS AGREEMENT AND THE OTHER CREDIT DOCUMENTS
SHALL BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE LAWS AND
DECISIONS OF THE STATE OF ILLINOIS, WITHOUT REGARD TO CONFLICT OF LAWS
PRINCIPLES.

      15.   JURISDICTION AND VENUE.  BORROWER AND EACH GUARANTOR HEREBY
AGREES THAT ALL ACTIONS OR PROCEEDINGS INITIATED BY BORROWER OR SUCH
GUARANTOR AND ARISING DIRECTLY OR INDIRECTLY OUT OF THIS AGREEMENT OR ANY
OTHER CREDIT DOCUMENT SHALL BE LITIGATED EITHER IN THE CIRCUIT COURT OF
COOK COUNTY, ILLINOIS OR IN THE UNITED STATES DISTRICT COURT FOR THE
NORTHERN DISTRICT OF ILLINOIS, OR IF BANK INITIATES SUCH ACTION, IN
ADDITION TO THE FOREGOING COURTS, ANY COURT IN WHICH BANK SHALL INITIATE OR
TO WHICH BANK SHALL REMOVE SUCH ACTION, TO THE EXTENT SUCH COURT HAS
JURISDICTION.  BORROWER AND EACH GUARANTOR HEREBY EXPRESSLY SUBMITS AND
CONSENT IN ADVANCE TO SUCH JURISDICTION IN ANY ACTION OR PROCEEDING
COMMENCED BY BANK IN OR REMOVED BY BANK TO ANY OF SUCH COURTS, AND HEREBY
AGREES THAT PERSONAL SERVICE OF THE SUMMONS AND COMPLAINT, OR OTHER PROCESS
OR PAPERS ISSUED THEREIN MAY BE MADE BY REGISTERED OR CERTIFIED MAIL
ADDRESSED TO BORROWER AT THE ADDRESS TO WHICH NOTICES ARE TO BE SENT
PURSUANT TO SECTION 11.1 OF THE CREDIT AGREEMENT.  BORROWER AND EACH
GUARANTOR WAIVES ANY CLAIM THAT THE CIRCUIT COURT OF COOK COUNTY, ILLINOIS
OR THE UNITED STATES DISTRICT COURT FOR THE NORTHERN DISTRICT OF ILLINOIS
IS AN INCONVENIENT FORUM OR AN IMPROPER FORUM BASED ON LACK OF VENUE.  THE
EXCLUSIVE CHOICE OF FORUM FOR BORROWER AND EACH GUARANTOR SET FORTH IN THIS
SECTION 15 SHALL NOT BE DEEMED TO PRECLUDE THE ENFORCEMENT BY BANK OF ANY
JUDGMENT OBTAINED IN ANY OTHER FORUM OR THE TAKING BY BANK OF ANY ACTION TO
ENFORCE THE SAME IN ANY OTHER APPROPRIATE JURISDICTION, AND BORROWER AND
EACH GUARANTOR HEREBY WAIVES THE RIGHT TO COLLATERALLY ATTACK ANY SUCH
JUDGMENT OR ACTION.

      16.   WAIVER OF RIGHT TO JURY TRIAL.  BANK, BORROWER AND EACH
GUARANTOR ACKNOWLEDGE AND AGREE THAT ANY CONTROVERSY WHICH MAY ARISE UNDER
ANY OF THE CREDIT DOCUMENTS OR WITH RESPECT TO THE TRANSACTIONS
CONTEMPLATED THEREBY WOULD BE BASED UPON DIFFICULT AND COMPLEX ISSUES AND,
THEREFORE, THE PARTIES AGREE THAT ANY LAWSUIT ARISING OUT OF ANY SUCH
CONTROVERSY WILL BE TRIED IN A COURT OF COMPETENT JURISDICTION BY A JUDGE
SITTING WITHOUT A JURY.


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      IN WITNESS WHEREOF, this Agreement has been executed and delivered by
each of the parties hereto by a duly authorized officer of each such party
on the date first set forth above.


                              LANDAUER, INC., a Delaware corporation

                              By:
                                    ------------------------------

                              Name:
                                    ------------------------------

                              Title:
                                    ------------------------------


                              HOMEBUYER'S PREFERRED, INC.,
                              an Illinois corporation

                              By:
                                    ------------------------------

                              Name:
                                    ------------------------------

                              Title:
                                    ------------------------------


                              HEALTHY HOME AIR, INC.,
                              a Delaware corporation

                              By:
                                    ------------------------------

                              Name:
                                    ------------------------------

                              Title:
                                    ------------------------------


                              LANDAUER INTERNATIONAL LLC,
                              a Delaware limited liability company

                              By:
                                    ------------------------------

                              Name:
                                    ------------------------------

                              Title:
                                    ------------------------------


                              LASALLE BANK NATIONAL ASSOCIATION,
                              a national banking association

                              By:
                                    ------------------------------

                              Name:
                                    ------------------------------

                              Title:
                                    ------------------------------



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