1
                                                                 EXHIBIT 4.6(a)



                     SUPPLEMENT TO THE AMENDED AND RESTATED
                            SENIOR PLEDGE AGREEMENT

     This Supplement No. 1 dated as of August 5, 1996, (this "Supplement") to
the Pledge Agreement (as defined below) is by IDEX Corporation, a Delaware
corporation (the "Pledgor"), in favor of Bank of America Illinois, as Agent (as
defined in the Pledge Agreement) under the Pledge Agreement for the benefit of
the secured parties thereunder.

                                   RECITALS:

     A. The Pledgor, the Agent and the Banks (as defined in the Pledge
Agreement) entered into that certain Third Amended and Restated Credit
Agreement dated as of July 17, 1996.  The Third Amended and Restated Credit
Agreement as now in effect or hereafter extended, renewed, modified,
supplemented, amended or restated is hereinafter called the "Credit Agreement".

     B. The Pledgor is a party to that certain Amended and Restated Pledge
Agreement dated as of July 17, 1996 (as amended, restated, supplemented or
otherwise modified from time to time, the "Pledge Agreement") with Bank of
America Illinois, as Agent for the financial institutions from time to time
party to that certain Credit Agreement.  Unless otherwise defined herein, each
capitalized term used herein shall have the meaning assigned thereto in the
Pledge Agreement or, if not defined therein, as defined in the Credit Agreement
referred to in the Pledge Agreement.

     C. Pursuant to Section 6.4 of the Pledge Agreement, this Supplement is
required to be executed and delivered to the Agent.

     In consideration of the premises above and as set forth in the Pledge
Agreement, the parties hereto agree as follows:

                                   ARTICLE I
                         SUPPLEMENT TO PLEDGE AGREEMENT

     1.1 Supplement to Pledge Agreement.  In accordance with Section 6.4 of the
Pledge Agreement, Pledgor, by its execution and delivery of this Supplement,
hereby (a) represents and warrants that the representations and warranties made
by it as a Pledgor under the Pledge Agreement are true and correct in all
material respects on and as of the date hereof and (b) agrees that the
Schedules hereto (which are designated as supplements to the corresponding
Schedules of the Pledge Agreement) are hereby incorporated in their entirety
into such corresponding Schedules of the Pledge Agreement.  Each reference to
"Pledged Notes," "Pledged Shares" and "Pledged Property" in the Pledge
Agreement shall be deemed to include the Pledged Notes, Pledged Shares and
Pledged Property pledged herein.


     1.2 Additional Representations, Warranties and Covenants.  Pledgor
represents and warrants to the Agent and the Banks that this Supplement has
been duly authorized, executed and delivered by it and constitutes its legal,
valid and binding obligation, enforceable against it in accordance with its
terms.

   2


                                   ARTICLE II
                               SECURITY INTERESTS

  2.1  Grant of Security Interest.

       (a) As security for payment of all Obligations of such Pledgor, Pledgor
hereby ratifies and confirms its pledge and grant of a security interest
pursuant to the Pledge Agreement and hereby pledges, assigns and transfers to
Agent and grants to Agent a continuing security interest in and to the shares
of capital stock and/or promissory notes identified on Schedules I and II
attached hereto together with all Dividends, Distributions, interest and other
payments and rights with respect thereto and all proceeds of any of the
foregoing (all of the items referred to in this Section 2.1 being herein called
the "Collateral").  The parties agree that such capital stock and/or promissory
notes shall be Pledged Shares or Pledged Notes pursuant to the Pledge Agreement
and shall be subject to the terms and conditions of the Pledge Agreement.

     (b) All advances, charges, costs and expenses, including reasonable
attorneys' fees, incurred or paid by Agent in exercising any right, power or
remedy conferred by this Agreement, or in the enforcement hereof or thereof,
shall, to the extent lawful, become a part of the Obligations secured hereby.

     (c) The Pledged Notes listed on Schedule I hereto and the certificates
representing the Pledged Shares listed on Schedule II hereto shall be delivered
to the Agent contemporaneously herewith together with appropriate undated note
powers and stock powers duly executed in blank.  Neither the Agent nor any Bank
shall be obligated to preserve or protect any rights with respect to the
Pledged Notes or the Pledged Shares or to receive or give any notice with
respect thereto whether or not the Agent or any Bank (other than the Pledgor)
is deemed to have knowledge of such matters.

     (d) The assignments and security interests under this Supplement granted
to the Agent shall not relieve Pledgor from the performance of any term,
covenant, condition or agreement on Pledgor's part to be performed or observed
under or in respect of any of the Collateral pledged by it hereunder or from
any liability to any Person under or in respect of any of such Collateral or
impose any obligation on the Agent to perform or observe any such term,
covenant, condition or agreement on Pledgor's part to be so performed or
observed or impose any liability on the Agent for any act or omission on the
part of Pledgor relative thereto or for any breach of any representation or
warranty on the part of Pledgor contained in this Supplement, the Pledge
Agreement or any other Loan Document, or in respect of the Collateral pledged
by it hereunder or made in connection herewith or therewith.  The obligations   
of Pledgor contained in this paragraph shall survive the termination of the
Pledge Agreement and the discharge of Pledgor's other obligations thereunder.

     (e) Pledgor agrees, at its own expense, to execute, acknowledge and
deliver, or cause the execution, acknowledgment and delivery of, and thereafter
to register, file or record in any and all appropriate governmental offices,
any and all documents and instruments reasonably deemed by the Agent to be
necessary or desirable for the creation and perfection of 

                                      2

   3

the foregoing security interests granted pursuant hereto.  Pledgor further
agrees to take all actions reasonably requested by the Agent (including,
without limitation, the filing of UCC-1 financing statements) in connection
with the granting of such security interests.  Pledgor agrees to pay in full
all taxes, fees and other charges payable in connection with the actions
described in this clause (e).

     2.2 Power of Attorney.  Pledgor hereby constitutes and appoints the Agent
its true and lawful attorney, irrevocably, with full power after the occurrence
of and during the continuance of a Default Event (in the name of Pledgor or
otherwise), in the Agent's discretion, to take any action and to execute any
instrument which the Agent may reasonably deem necessary or advisable to
accomplish the purposes of the Pledge Agreement, which appointment as attorney
is coupled with an interest.

                                  ARTICLE III
                                 MISCELLANEOUS

     3.1 Miscellaneous Provisions.  Each of the provisions set forth in
Sections 6.1 through 6.17 (inclusive) of the Pledge Agreement is hereby
incorporated by reference mutatis mutandis with the same effect as if such
provisions had been set forth herein with each reference therein to "this
Agreement" deemed to be a reference to "this Supplement" and each reference to
a "Pledgor" deemed to be a reference to "Pledgor".


                            [SIGNATURE PAGE FOLLOWS]




                                       3


   4


     IN WITNESS WHEREOF, the parties hereto have caused this Supplement No. 1
to the Pledge Agreement to be duly and properly executed and delivered as of
the date first written above.

                                   IDEX Corporation


                                   By:   /s/  WAYNE P. SAYATOVIC
                                      --------------------------
                                   Name:  Wayne P. Sayatovic
                                   Title: Senior Vice President - Finance,
                                          Chief Financial Officer and Secretary

                                   Address:  630 Dundee Road, Suite 400
                                             Northbrook, Illinois 60065


                                   Attention:  Douglas C. Lennox
                                   Facsimile No.:  312/498-3940

Accepted:

BANK OF AMERICA ILLINOIS,
as Agent


By:
   ----------------------------------
Title:
      -------------------------------



                                       4


   5




                        SCHEDULE I (to Supplement No. 1)

                                 PLEDGED NOTES


                                               Principal Amount of
               Subsidiary             Date     Intercompany Note
              ----------------------  -------  -------------------

              Fluid Management, Inc.  7/29/96  $100,000,000




                                      5

   6

                       SCHEDULE II (to Supplement No. 1)

                                 PLEDGED SHARES



                                                Capital Stock
                                     ------------------------------------
        Subsidiary Issuer            Number of Shares  Certificate Number
       ----------------------------  ----------------  ------------------

       FMI Management Company              1000               1
        (f/k/a The Saranow Company)

       Fluid Management, Inc.               100               1
        (f/k/a FM Acquistion Corp)





                                      6