EXHIBIT 3.1
 
                              AMENDED AND RESTATED
                           ARTICLES OF INCORPORATION
 
                                       OF
 
                                  ITRON, INC.
 
     Pursuant to RCW 23B.10.070,  the following constitutes Amended and Restated
Articles of Incorporation of the undersigned, a Washington corporation.
 
                                ARTICLE 1. NAME
 
     The name of this corporation is Itron, Inc.
 
                               ARTICLE 2. SHARES
 
     2.1  AUTHORIZED CAPITAL
 
     The total number of shares which the corporation is authorized to issue is
85,000,000, consisting of 75,000,000 shares of Common Stock without par value
and 10,000,000 shares of Preferred Stock without par value. The Common Stock is
subject to the rights and preferences of the Preferred Stock as hereinafter set
forth.
 
     2.2  ISSUANCE OF PREFERRED STOCK IN SERIES
 
     The Preferred Stock may be issued from time to time in one or more series
in any manner permitted by law and the provisions of these Articles of
Incorporation of the corporation, as determined from time to time by the Board
of Directors and stated in the resolution or resolutions providing for the
issuance thereof, prior to the issuance of any shares thereof. The Board of
Directors shall have the authority to fix and determine and to amend, subject to
the provisions hereof, the designation, preferences, limitations and relative
rights of the shares of any series that is wholly unissued or to be established.
Unless otherwise specifically provided in the resolution establishing any
series, the Board of Directors shall further have the authority, after the
issuance of shares of a series whose number it has designated, to amend the
resolution establishing such series to decrease the number of shares of that
series, but not below the number of shares of such series then outstanding.
 
     2.3  DIVIDENDS
 
     The holders of shares of the Preferred Stock shall be entitled to receive
dividends, out of the funds of the corporation legally available therefor, at
the rate and at the time or times, whether cumulative or noncumulative, as may
be provided by the Board of Directors in designating a particular series of
Preferred Stock. If such dividends on the Preferred Stock shall be cumulative,
then if dividends shall not have been paid, the deficiency shall be fully paid
or the dividends declared and set apart for payment at such rate, but without
interest on
 
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cumulative dividends, before any dividends on the Common Stock shall
be paid or declared and set apart for payment. The holders of the Preferred
Stock shall not be entitled to receive any dividends thereon other than the
dividends referred to in this section.
 
     2.4  REDEMPTION
 
     The Preferred Stock may be redeemable at such price, in such amount, and at
such time or times as may be provided by the Board of Directors in designating a
particular series of Preferred Stock. In any event, such Preferred Stock may be
repurchased by the corporation to the extent legally permissible.
 
     2.5  LIQUIDATION
 
     In the event of any liquidation, dissolution, or winding up of the affairs
of the corporation, whether voluntary or involuntary, then, before any
distribution shall be made to the holders of the Common Stock, the holders of
the Preferred Stock at the time outstanding shall be entitled to be paid the
preferential amount or amounts per share as may be provided by the Board of
Directors in designating a particular series of Preferred Stock and dividends
accrued thereon to the date of such payment. The holders of the Preferred Stock
shall not be entitled to receive any distributive amounts upon the liquidation,
dissolution, or winding up of the affairs of the corporation other than the
distributive amounts referred to in this section, unless otherwise provided by
the Board of Directors in designating a particular series of Preferred Stock.
 
     2.6  CONVERSION
 
     Shares of Preferred Stock may be convertible into Common Stock of the
corporation upon such terms and conditions, at such rate and subject to such
adjustments as may be provided by the Board of Directors in designating a
particular series of Preferred Stock.
 
     2.7  VOTING RIGHTS
 
     Holders of Preferred Stock shall have such voting rights as may be provided
by the Board of Directors in designating a particular series of Preferred Stock.
 
     2.8  DESIGNATION OF RIGHTS AND PREFERENCES OF SERIES R PARTICIPATING
          CUMULATIVE PREFERRED STOCK
 
     The following series of Preferred Stock is hereby designated, which series
shall have the rights, preferences and privileges and limitations set forth
below:
 
          2.8.1     DESIGNATION OF SERIES R PARTICIPATING CUMULATIVE PREFERRED
                    STOCK
 
     The shares of such series shall be designated the "Series R Participating
Cumulative Preferred Stock" (the "Series R Preferred Stock"), without par value.
The number of shares initially constituting the Series R Preferred Stock shall
be 1,000,000; provided, however, if
 
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more than a total of 1,000,000 shares of Series R Preferred Stock shall be
issuable upon the exercise of Rights (the "Rights") issued pursuant to the
Rights Agreement dated as of December 11, 2002 between the corporation and
Mellon Investor Services LLC, as Rights Agent (the "Rights Agreement"), the
corporation's Board of Directors, pursuant to Section 23B.06.020 of the Revised
Code of Washington, shall direct by resolution or resolutions that Articles of
Amendment be properly executed and filed with the Washington Secretary of State
providing for the total number of shares of Series R Preferred Stock authorized
for issuance to be increased (to the extent that the Amended and Restated
Articles of Incorporation then permits) to the largest number of whole shares
(rounded up to the nearest whole number) issuable upon exercise of such Rights.
In addition, such number of shares may be decreased by resolution of the Board
of Directors; provided, however, that no decrease shall reduce the number of
shares of Series R Preferred Stock to a number less than the number of shares
then outstanding plus the number of shares reserved for issuance upon the
exercise of outstanding options, rights or warrants or upon the conversion of
any outstanding securities issued by the corporation convertible into Series R
Preferred Stock.
 
          2.8.2     DIVIDENDS AND DISTRIBUTIONS
 
          (a) Subject to the prior and superior rights of the holders of shares
of any other series of Preferred Stock or other class of capital stock of the
corporation ranking prior and superior to the shares of Series R Preferred Stock
with respect to dividends, the holders of shares of Series R Preferred Stock
shall be entitled to receive, when, as, and if declared by the Board of
Directors, out of the assets of the corporation legally available therefor,
quarterly dividends payable in cash on the last day of each fiscal quarter in
each year, or such other dates as the corporation's Board of Directors shall
approve (each such date being referred to in this Designation as a "Quarterly
Dividend Payment Date"), commencing on the first Quarterly Dividend Payment Date
after the first issuance of a share or a fraction of a share of Series R
Preferred Stock, in an amount per share (rounded to the nearest cent) equal to
the greater of (i) $0.01 and (ii) the Formula Number (as hereinafter defined)
then in effect times the cash dividends then to be paid on each share of Common
Stock. In addition, if the corporation shall pay any dividend or make any
distribution on the Common Stock payable in assets, securities or other forms of
noncash consideration (other than dividends or distributions solely in shares of
Common Stock), then, in each such case, the corporation shall simultaneously pay
or make on each outstanding whole share of Series R Preferred Stock a dividend
or distribution in like kind equal to the Formula Number then in effect times
such dividend or distribution on each share of Common Stock. As used in this
Designation and in the Rights Agreement, the "Formula Number" shall be 100;
provided, however, that if at any time after December 11, 2002 the corporation
shall (i) declare or pay any dividend on the Common Stock payable in shares of
Common Stock or make any distribution on the Common Stock in shares of Common
Stock, (ii) subdivide (by a stock split or otherwise) the outstanding shares of
Common Stock into a larger number of shares of Common Stock, or (iii) combine
(by a reverse stock split or otherwise) the outstanding shares of Common Stock
into a smaller number of shares of Common Stock, then in each such event the
Formula Number shall be adjusted to a number determined by multiplying the
Formula Number in effect immediately prior to such event by a fraction, the
numerator of which is the number of shares of Common Stock that are outstanding
immediately after such event and the
 
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denominator of which is the number of shares of Common Stock that are
outstanding immediately prior to such event (and rounding the result to the
nearest whole number); and provided further, that if at any time after December
11, 2002 the corporation shall issue any shares of its capital stock in a
merger, reclassification or change of the outstanding shares of Common Stock,
then in each such event the Formula Number shall be appropriately adjusted to
reflect such merger, reclassification or change so that each share of Preferred
Stock continues to be the economic equivalent of a Formula Number of shares of
Common Stock prior to such merger, reclassification or change.
 
          (b) The Corporation shall declare a dividend or distribution on the
Series R Preferred Stock as provided in Section 2.8.2(a) immediately prior to or
at the same time it declares a dividend or distribution on the Common Stock
(other than a dividend or distribution solely in shares of Common Stock);
provided, however, that in the event no dividend or distribution (other than a
dividend or distribution in shares of Common Stock) shall have been declared on
the Common Stock during the period between any Quarterly Dividend Payment Date
and the next subsequent Quarterly Dividend Payment Date, a dividend of $0.01 per
share on the Series R Preferred Stock shall nevertheless be payable on such
subsequent Quarterly Dividend Payment Date. The Corporation's Board of Directors
may fix a record date for the determination of holders of shares of Series R
Preferred Stock entitled to receive a dividend or distribution declared thereon,
which record date shall be the same as the record date for any corresponding
dividend or distribution on the Common Stock and which shall not be more than 60
days prior to the date fixed for payment thereof.
 
          (c) Dividends shall begin to accrue and be cumulative on outstanding
shares of Series R Preferred Stock from and after the Quarterly Dividend Payment
Date next preceding the date of original issue of such shares of Series R
Preferred Stock; provided, however, that dividends on such shares that are
originally issued after the record date for the determination of holders of
shares of Series R Preferred Stock entitled to receive a quarterly dividend on
or prior to the next succeeding Quarterly Dividend Payment Date shall begin to
accrue and be cumulative from and after such Quarterly Dividend Payment Date.
Notwithstanding the foregoing, dividends on shares of Series R Preferred Stock
that are originally issued prior to the record date for the determination of
holders of shares of Series R Preferred Stock entitled to receive a quarterly
dividend on or prior to the first Quarterly Dividend Payment Date shall be
calculated as if cumulative from and after the last day of the fiscal quarter
(or such other Quarterly Dividend Payment Date as the corporation's Board of
Directors shall approve) next preceding the date of original issuance of such
shares. Accrued but unpaid dividends shall not bear interest. Dividends paid on
the shares of Series R Preferred Stock in an amount less than the total amount
of such dividends at the time accrued and payable on such shares shall be
allocated pro rata on a share-by-share basis among all such shares at the time
outstanding.
 
          (d) So long as any shares of Series R Preferred Stock are outstanding,
no dividends or other distributions shall be declared, paid or distributed, or
set aside for payment or distribution, on the Common Stock unless, in each case,
the dividend required by this Section 2.8.2 to be declared on the Series R
Preferred Stock shall have been declared.
 
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          (e) The holders of shares of Series R Preferred Stock shall not be
entitled to receive any dividends or other distributions except as provided in
this Designation.
 
          2.8.3     VOTING RIGHTS
 
     The holders of shares of Series R Preferred Stock shall have the
following voting rights:
 
          (a) Each holder of Series R Preferred Stock shall be entitled to a
number of votes equal to the Formula Number then in effect for each share of
Series R Preferred Stock held of record on each matter on which holders of the
Common Stock or shareholders generally are entitled to vote, multiplied by the
maximum number of votes per share that any holders of the Common Stock or
shareholders generally then have with respect to such matter (assuming any
holding period or other requirement to vote a greater number of shares is
satisfied).
 
          (b) Except as otherwise provided in this Designation or by applicable
law, the holders of shares of Series R Preferred Stock and the holders of shares
of Common Stock and any other capital stock of the corporation having general
voting rights shall vote together as one class for the election of directors of
the corporation and on all other matters submitted to a vote of shareholders of
the corporation.
 
          (c) Except as provided in this Designation or by applicable law,
holders of Series R Preferred Stock shall have no special voting rights and
their consent shall not be required (except to the extent they are entitled to
vote with holders of Common Stock as set forth in this Designation) for
authorizing or taking any corporate action.
 
          2.8.4     CERTAIN RESTRICTIONS
 
          (a) Whenever quarterly dividends or other dividends or distributions
payable on the Series R Preferred Stock as provided in Section 2.8.2 are in
arrears, thereafter and until all accrued and unpaid dividends and
distributions, whether or not declared, on shares of Series R Preferred Stock
outstanding shall have been paid in full, the corporation shall not:
 
               (i)   declare or pay dividends on, make any other distributions
on, or redeem or purchase or otherwise acquire for consideration any shares of
stock ranking junior (either as to dividends or upon liquidation, dissolution or
winding up) to the Series R Preferred Stock;
 
               (ii)  declare or pay dividends on or make any other distributions
on any shares of stock ranking on a parity (either as to dividends or upon
liquidation, dissolution or winding up) with the Series R Preferred Stock,
except dividends paid ratably on the Series R Preferred Stock and all such
parity stock on which dividends are payable or in arrears in proportion to the
total amounts to which the holders of all such shares are then entitled;
 
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<PAGE>
 
               (iii) redeem or purchase or otherwise acquire for consideration
     shares of any stock ranking junior (either as to dividends or upon
     liquidation, dissolution or winding up) with the Series R Preferred Stock;
     provided, however, that the corporation may at any time redeem, purchase or
     otherwise acquire shares of any such junior stock in exchange for shares of
     any stock of the corporation ranking junior (either as to dividends or upon
     dissolution, liquidation or winding up) to the Series R Preferred Stock; or
 
               (iv)  redeem or purchase or otherwise acquire for consideration
     any shares of Series R Preferred Stock, or any shares of stock ranking on a
     parity with the Series R Preferred Stock, except in accordance with a
     purchase offer made in writing or by publication (as determined by the
     corporation's Board of Directors) to all holders of such shares upon such
     terms as the corporation's Board of Directors, after consideration of the
     respective annual dividend rates and other relative rights and preferences
     of the respective Preferred Stock classes, shall determine in good faith
     will result in fair and equitable treatment among the respective series or
     classes.
 
          (b) The corporation shall not permit any subsidiary of the corporation
to purchase or otherwise acquire for consideration any shares of stock of the
corporation unless the corporation could, under paragraph (a) of this Section
2.8.4, purchase or otherwise acquire such shares at such time and in such
manner.
 
          2.8.5     LIQUIDATION RIGHTS
 
     Upon the liquidation, dissolution or winding up of the corporation, whether
voluntary or involuntary, no distribution shall be made to (a) the holders of
shares of stock ranking junior (either as to dividends or upon liquidation,
dissolution or winding up) to the Series R Preferred Stock unless, prior
thereto, the holders of shares of Series R Preferred Stock shall have received
an amount equal to the greater of (i) $.01 per share and (ii) the accrued and
unpaid dividends and distributions thereon, whether or not declared, to the date
of such payment, plus an aggregate amount per share equal to the Formula Number
then in effect times the aggregate amount to be distributed per share to holders
of Common Stock or (b) the holders of shares of stock ranking on a parity
(either as to dividends or upon liquidation, dissolution or winding up) with the
Series R Preferred Stock, except distributions made ratably on the Series R
Preferred Stock and all other such parity stock in proportion to the total
amounts to which the holders of all such shares are entitled upon such
liquidation, dissolution or winding up.
 
          2.8.6     CONSOLIDATION, MERGER, ETC.
 
     In case the corporation shall enter into any consolidation, merger,
combination or other transaction in which the shares of Common Stock are
exchanged for or changed into other stock or securities, cash and/or any other
property, then in any such case the then outstanding shares of Series R
Preferred Stock shall at the same time be similarly exchanged or changed into an
amount per share equal to the Formula Number then in effect times the aggregate
amount of stock, securities, cash and/or any other property (payable in kind),
as the
 
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<PAGE>
 
case may be, into which or for which each share of Common Stock is exchanged or
changed. In the event both this Section 2.8.6 and Section 2.8.2 appear to apply
to a transaction, this Section 2.8.6 will control.
 
          2.8.7     NO REDEMPTION; NO SINKING FUND
 
          (a) The shares of Series R Preferred Stock shall not be subject to
redemption by the corporation or at the option of any holder of Series R
Preferred Stock; provided, however, that the corporation may purchase or
otherwise acquire outstanding shares of Series R Preferred Stock in the open
market or by offer to any holder or holders of shares of Series R Preferred
Stock.
 
          (b) The shares of Series R Preferred Stock shall not be subject to or
entitled to the operation of a retirement or sinking fund.
 
          2.8.8     RANKING
 
     The Series R Preferred Stock shall rank junior to all other series of
Preferred Stock of the corporation, unless the corporation's Board of Directors
shall specifically determine otherwise in fixing the powers, preferences and
relative, participating, optional and other special rights of the shares of such
Preferred Stock and the qualifications, limitations and restrictions thereof.
 
          2.8.9     FRACTIONAL SHARES
 
     The Series R Preferred Stock shall be issuable upon exercise of the Rights
issued pursuant to the Rights Agreement in whole shares or in any fractional
share that is one one-hundredth (1/100th) of a share or any integral multiple of
such fraction, and shall entitle the holder, in proportion to such holder's
fractional shares, to receive dividends, exercise voting rights, participate in
distributions and have the benefit of all other rights of holders of Series R
Preferred Stock. In lieu of fractional shares, the corporation, prior to the
first issuance of a share or a fractional share of Series R Preferred Stock, may
elect to (a) make a cash payment as provided in the Rights Agreement for a
fractional share other than one one-hundredth (1/100th) of a share or any
integral multiple thereof or (b) issue depository receipts evidencing such
authorized fractional share of Series R Preferred Stock pursuant to an
appropriate agreement between the corporation and a depository selected by the
corporation; provided, however, that such agreement shall provide that the
holders of such depository receipts shall have all the rights, privileges and
preferences to which they are entitled as holders of the Series R Preferred
Stock.
 
          2.8.10    REACQUIRED SHARES
 
     Any shares of Series R Preferred Stock purchased or otherwise acquired by
the corporation in any manner whatsoever shall be retired and canceled promptly
after the acquisition thereof. All such shares shall upon their cancellation
become authorized but unissued shares of Preferred Stock, without designation as
to series until such shares are once
 
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more designated as part of a particular series by the corporation's Board of
Directors pursuant to the provisions of Article 2 of the Amended and Restated
Articles of Incorporation.
 
          2.8.11    AMENDMENT
 
     None of the powers, preferences and relative, participating, optional and
other special rights of the Series R Preferred Stock as provided herein shall be
amended in any manner that would alter or change the powers, preferences, rights
or privileges of the holders of Series R Preferred Stock so as to affect them
adversely without the affirmative vote of the holders of at least two-thirds of
the outstanding shares of Series R Preferred Stock, voting as a separate class.
 
              ARTICLE 3. REGISTERED OFFICE AND AGENT
 
     The name of the registered agent of this corporation and the address of its
registered office are as follows:
 
                      Lawco of Washington, Inc.
                      1201 Third Avenue, 40th Floor
                      Seattle, Washington 98101-3099
 
                    ARTICLE 4. PREEMPTIVE RIGHTS
 
     No preemptive rights shall exist with respect to shares of stock or
securities convertible into shares of stock of this corporation.
 
                    ARTICLE 5. CUMULATIVE VOTING
 
     The right to cumulate votes in the election of Directors shall not exist
with respect to shares of stock of this corporation.
 
                    ARTICLE 6. DIRECTORS
 
     The number of Directors of this corporation shall be determined in the
manner provided by the Bylaws and may be increased or decreased from time to
time in the manner provided therein. The Directors of this corporation may be
removed only for cause in the manner provided by the Bylaws.
 
     At the 1992 annual election of Directors, the Board of Directors shall be
divided into three classes (said classes to be as equal in number as may be
possible) with the following classes being elected for the terms set forth
below:
 
              CLASS                                TERM
              -----                                ----
             Class 1                              1 year
             Class 2                              2 years
             Class 3                              3 years
 
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     Subsequent to the 1992 annual election of Directors, a Director's term
shall be three years, and each Director shall serve for the term for which he or
she was elected, or until his or her successor shall have been elected and
qualified, or until his or her death, resignation or removal from office;
provided, however, that despite the expiration of a Director's term, a Director
shall continue to serve until his or her successor is elected or until there is
a decrease in the authorized number of Directors. Directors need not be
shareholders of the corporation or residents of the State of Washington and need
not meet any other qualifications.
 
                    ARTICLE 7. BYLAWS
 
     The Board of Directors shall have the power to adopt, amend or repeal the
Bylaws of this corporation, subject to the power of the shareholders to amend or
repeal such Bylaws. The shareholders shall also have the power to amend or
repeal the Bylaws of this corporation and to adopt new Bylaws.
 
                    ARTICLE 8. AMENDMENTS TO ARTICLES OF INCORPORATION
 
     This corporation reserves the right to amend or repeal any of the
provisions contained in these Amended and Restated Articles of Incorporation in
any manner now or hereafter permitted by law, and the rights of the shareholders
of this corporation are granted subject to this reservation.
 
                    ARTICLE 9. LIMITATION OF DIRECTOR LIABILITY
 
     To the full extent that the Washington Business Corporation Act, as it
exists on the date hereof or may hereafter be amended, permits the limitation or
elimination of the liability of Directors, a Director of this corporation shall
not be liable to this corporation or its shareholders for monetary damages for
conduct as a Director. Any amendments to or repeal of this Article 9 shall not
adversely affect any right or protection of a Director of this corporation for
or with respect to any acts or omissions of such Director occurring prior to
such amendment or repeal.
 
     Dated: December 11, 2002
 
                                                   /s/ MariLyn R. Blair
                                              --------------------------------
                                                 MariLyn R. Blair, Secretary
 
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                            CERTIFICATE ACCOMPANYING
 
                              AMENDED AND RESTATED
 
                           ARTICLES OF INCORPORATION
 
                                       OF
 
                                  ITRON, INC.
 
     Pursuant to RCW 23B.10.070, the undersigned hereby certifies on behalf of
Itron, Inc., a Washington corporation (the "Corporation"), as follows:
 
     1.   The name of the Corporation is Itron, Inc.
 
     2.   The Articles of Incorporation of the Corporation, as amended, are
amended and restated in their entirety to read as set forth in the attached
Amended and Restated Articles of Incorporation.
 
     3.   The amendment was duly adopted by the Board of Directors of the
Corporation on November 4, 2002. Shareholder action is not required in
connection with this amendment.
 
     These Amended and Restated Articles of Incorporation are executed by the
Corporation by its duly authorized officer.
 
     Dated: December 11, 2002.
 
                                              ITRON, INC.
 
                                              By:     /s/ MariLyn R. Blair
                                                 -------------------------------
                                                 MariLyn R. Blair
                                                 Secretary