Exhibit (a)(3)

Notice of Guaranteed Delivery

to

Tender Shares of Common Stock

(including the Associated Series B No Par Preferred Shares Purchase Rights)

of

Tektronix, Inc.

to

Raven Acquisition Corp.

An indirect wholly owned subsidiary of

Danaher Corporation

(Not to be Used for Signature Guarantees)

This Notice of Guaranteed Delivery or one substantially equivalent hereto must be used to accept the Offer (as defined below) if certificates for Shares (as defined below) are not immediately available or the certificates for Shares and all other required documents cannot be delivered to Computershare Trust Company, N.A. (the “Depositary”) on or prior to the Expiration Date (as defined in the Offer to Purchase) or if the procedure for delivery by book-entry transfer cannot be completed on a timely basis. This instrument may be transmitted by facsimile transmission or mailed to the Depositary. See Section 3 of the Offer to Purchase.

The Depositary for the Offer is:

Computershare Trust Company, N.A.

Facsimile for Eligible Institutions:

(617) 360-6810

Confirm by Telephone:

(781) 575-2332

By Mail:	By Overnight Courier:
Computershare Trust Company, N.A.	Computershare Trust Company, N.A.
Attn: Corporate Actions	Attn: Corporate Actions
P.O. Box 43011	250 Royall Street
Providence, RI 02940-3011	Canton, MA 02021

Delivery of this Notice of Guaranteed Delivery to an address other than as set forth above or transmission of instructions via facsimile transmission other than as set forth above will not constitute a valid delivery to the Depositary.

This form is not to be used to guarantee signatures. If a signature on a Letter of Transmittal is required to be guaranteed by an Eligible Institution under the instructions thereto, such signature guarantee must appear in the applicable space provided in the signature box in the Letter of Transmittal.

The guarantee on the reverse side must be completed.

Scan: Voluntary Corp. Actions

Ladies and Gentlemen:

The undersigned hereby tender(s) to Raven Acquisition Corp., an Oregon corporation and an indirect wholly owned subsidiary of Danaher Corporation, a Delaware corporation, upon the terms and subject to the conditions set forth in the Offer to Purchase, dated October 18, 2007 (the “Offer to Purchase”), and in the related Letter of Transmittal (which, as amended from time to time, together constitute the “Offer”), receipt of which is hereby acknowledged, the number of shares of common stock, without par value, including the Associated Series B No Par Preferred Shares Purchases Rights (the “Shares”), of Tektronix, Inc., an Oregon corporation, indicated below pursuant to the guaranteed delivery procedure set forth in Section 3 of the Offer to Purchase.

Number of Tendered Shares:

Certificate No.(s) (if available):

Check box if Shares will be tendered by book-entry transfer: ¨

Name of Tendering Institution:

Dated:                     , 2007

Name(s) of Record Holder(s):

(Please Print)

Address(es):

(Zip Code)

Area Code and Telephone No.(s):

SIGN HERE

Signature(s):

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GUARANTEE

(NOT TO BE USED FOR SIGNATURE GUARANTEE)

The undersigned, a firm that is a bank, broker, dealer, credit union, savings association or other entity that is a member in good standing of a recognized Medallion Program approved by the Securities Transfer Association Inc., including the Securities Transfer Agents Medallion Program (“STAMP”), the Stock Exchange Medallion Program (“SEMP”) and the New York Stock Exchange Medallion Signature Program (“MSP”) or any other “eligible guarantor institution” (as such term is defined in Rule 17Ad-15 under the Securities Exchange Act of 1934, as amended), guarantees to deliver to the Depositary either the certificates evidencing all tendered Shares, in proper form for transfer, or a Book-Entry Confirmation (as defined in the Offer to Purchase) with respect to such Shares, in either case, together with the Letter of Transmittal (or a facsimile thereof), properly completed and duly executed, with any required signature guarantees or an Agent’s Message (as defined in the Offer to Purchase) in the case of a book-entry delivery, and any other required documents, all within three New York Stock Exchange trading days after the date hereof.

The eligible guarantor institution that completes this form must communicate the guarantee to the Depositary and must deliver the Letter of Transmittal and Share Certificates to the Depositary within the time period indicated herein. Failure to do so may result in financial loss to such eligible guarantor institution.

Name of Firm:                                                                                                                             

(Authorized Signature)

Address:                                                                                                                                        

(Zip Code)

Title:                                                                                                                                               

Name:                                                                                                                                            

(Please Print or Type)

Area Code and Telephone No.:                                                                                             

Dated:                     , 2007

NOTE: DO NOT SEND CERTIFICATES FOR SHARES WITH THIS NOTICE. SHARE CERTIFICATES SHOULD BE SENT WITH YOUR LETTER OF TRANSMITTAL.

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