
<PAGE>

                                                                    EXHIBIT 99.3

                            DIAMETRICS MEDICAL, INC.

                             STOCK PURCHASE WARRANT

THE WARRANTS EVIDENCED HEREBY AND THE SHARES OF STOCK ISSUABLE UPON EXERCISE
THEREOF HAVE NOT BEEN REGISTERED UNDER SECURITIES ACT OF 1933, AS AMENDED, AND
MAY NOT BE OFFERED OR SOLD WITHOUT REGISTRATION UNLESS AN EXEMPTION FROM
REGISTRATION IS AVAILABLE UNDER SUCH ACT OR THE RULES OR REGULATIONS PROMULGATED
THEREUNDER.

                                                                   June 28, 1999

                                     WARRANT

     To Subscribe for and Purchase Common Stock of Diametrics Medical, Inc.

         VOID AFTER 5:00 P.M., MINNEAPOLIS, MINNESOTA TIME, ON AUGUST 4,
        2003, OR IF NOT A BUSINESS DAY, AS DEFINED HEREIN, AT 5:00 P.M.,
           MINNEAPOLIS TIME, ON THE IMMEDIATELY PRECEDING BUSINESS DAY

     This certifies that, for valuable consideration, receipt of which is hereby
acknowledged, Hewlett-Packard Company, and permitted successors and assigns
("Holder") is entitled to purchase from Diametrics Medical, Inc. a Minnesota
corporation (the "Company") up to and including 452,381 fully paid and
nonassessable shares (the "Number of Shares") of the common stock of the
Company, $.01 par value (the "Common Stock"), on the terms set forth herein at
an exercise price per share equal to $8.40 (the "Purchase Price"). The Number of
Shares and the Purchase Price may be adjusted from time to time as described in
this Warrant.

1.   Exercise.

     1.1 Time for Exercise. This Warrant may be exercised in whole or in part at
any time, and from time to time, during the period commencing on the date of
this Warrant and expiring on August 4, 2003.

     1.2 Manner of Exercise. This Warrant shall be exercised by delivering it to
the Company with the exercise form duly completed and signed, specifying the
number of shares as to which the Warrant is being exercised at that time (the
"Exercise Number"). The Holder shall simultaneously deliver to the Company cash
or a certified check or wire transfer in an amount equal to the Exercise Number
multiplied by the Purchase Price, and the Holder shall be entitled to receive
the full Exercise Number of shares of Common Stock.

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     1.3 Effective Date of Exercise. Promptly (but in any case within ten
business days) after any exercise, the Company shall deliver to the Holder (a)
duly executed certificates in the name or names specified in the exercise notice
representing the aggregate number of shares issuable upon such exercise, and (b)
if this Warrant is exercised only in part, a new Warrant of like tenor
exercisable for the balance of the Number of Shares. Such certificates shall be
deemed to have been issued, and the person receiving them shall be deemed to be
a holder of record of such shares, as of the close of business on the date the
actions required in Section 1.2 shall have been completed or, if on that date
the stock transfer books of the Company are closed, as of the next business day.

2.   Transfer of Warrants and Stock.

     2.1 Transfer Restrictions. This Warrant shall be freely transferable by the
Holder in accordance with the terms hereof; provided, however, that neither this
Warrant nor the securities issuable upon its exercise may be sold, transferred
or pledged unless the Company shall have been supplied with reasonably
satisfactory evidence that such transfer is not in violation of the Securities
Act of 1933, as amended (the "Securities Act"), and any applicable state
securities laws. The Company may place a legend to that effect on this Warrant,
any replacement Warrant and each certificate representing shares issuable upon
exercise of this Warrant. Subject to the satisfaction of this condition only,
this Warrant shall be freely transferable by the Holder.

     2.2 Manner of Transfer. Upon delivery of this Warrant to the Company with
the assignment form duly completed and signed, the Company will promptly (but in
any case within five (5) business days) execute and deliver to each transferee
and, if applicable, the Holder, Warrants of like tenor evidencing the rights (a)
of the transferee(s) to purchase the Number of Shares specified for each in the
assignment forms, and (b) of the Holder to purchase any untransferred portion,
which in the aggregate shall equal the number of Shares of the original Warrant.
If this Warrant is properly assigned in compliance with Section 2, it may be
exercised by an assignee without having a new Warrant issued.

     2.3 Loss, Destruction of Warrant Certificates. Upon receipt of (a) evidence
reasonably satisfactory to the Company of the loss, theft, destruction or
mutilation of any Warrant and (b) except in the case of mutilation, an indemnity
or security reasonably satisfactory to the Company, the Company will promptly
(but in any case within five (5) business days) execute and deliver a
replacement Warrant of like tenor representing the right to purchase the same
Number of Shares.

3. Cost of Issuances. The Company shall pay all expenses, transfer taxes and
other charges payable in connection with the preparation, issuance and delivery
of stock certificates or replacement Warrants, except for any transfer tax or
other charge imposed as a result of (a) any issuance of certificates in any name
other than the name of the Holder, or (b) any transfer of the Warrant. The
Company shall not be required to issue or deliver any Stock certificate or
Warrant until it receives reasonably satisfactory evidence that any such tax or
other charge has been paid by the Holder.

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4. Anti-Dilution Provisions. If any of the following events occur at any time
hereafter during the life of this Warrant, then the Purchase Price and the
Number of Shares immediately prior to such event shall be changed as described
in order to prevent dilution:

     4.1 Dividends; Stock Splits Etc. In case the Company shall (a) pay a
dividend in shares of Common Stock or make a distribution in shares of Common
Stock, (b) subdivide or reclassify its outstanding shares of Common Stock into a
greater number of shares, or (c) combine or reclassify its outstanding shares of
Common Stock into a smaller number of shares, the Number of Shares purchasable
upon the exercise of this Warrant immediately prior thereto shall be adjusted so
that the Number of Shares purchasable upon exercise of this Warrant shall be
determined by multiplying the Number of Shares theretofore purchasable upon the
exercise of this Warrant by a fraction, of which the numerator shall be the
number of shares of Common Stock outstanding immediately following such action
and of which the denominator shall be the number of shares of Common Stock
outstanding immediately prior thereto. Such adjustment shall be made whenever
any event listed above shall occur and shall become effective immediately after
the record date in the case of a dividend and shall become effective immediately
after the effective date in the case of a subdivision, combination or
reclassification. If the Company declares a dividend in money on its Common
Stock and at substantially the same time offers its Stockholders a right to
purchase new shares of Common Stock or of capital stock of any other class from
the proceeds of such dividend, or for an amount substantially equal to such
dividend, all shares of Common Stock or of capital stock of any other class so
issued shall for purposes hereof be deemed issued as a Stock dividend.

     4.2 Issuance of Rights or Warrants to Holders. In case the Company shall
issue rights, options or warrants to all holders of its shares of Common Stock
entitling them (for a period expiring within 45 days after the record date
therefor) to subscribe for or purchase shares of Common Stock at a price per
share which is lower at the record date mentioned below than the then Current
Market Price per share of Common Stock (as hereinafter defined), the Number of
Shares thereafter purchasable upon the exercise of this Warrant shall be
determined by multiplying the Number of Shares theretofore purchasable upon
exercise of this Warrant by a fraction, of which the numerator shall be the
number of shares of Common Stock outstanding on such record date plus the number
of additional shares of Common Stock offered for subscription or purchase, and
of which the denominator shall be the number of shares of Common Stock
outstanding on such record date plus the number of shares which the aggregate
offering price of the total number shares of Common Stock so offered would
purchase at the then Current Market Price per share of Common Stock. For
purposes of this Section 4.2, the issuance of rights, options or warrants to
subscribe for or purchase securities convertible into Common Stock shall be
deemed to be the issuance of rights, options or warrants to purchase the Common
Stock into which such securities are convertible at an aggregate offering price
equal to the aggregate offering price of such securities plus the minimum
aggregate amount (if any) payable upon conversion of such securities into Common
Stock.

     4.3 Merger; Consolidation; Sale of Assets. In case of (a) the consolidation
or the merger of the Company, (b) the sale of all or substantially all of the
properties and assets of the Company to any Person, (c) any capital
reorganization by the Company, or (d) any voluntary or

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involuntary dissolution, liquidation, or winding up of the Company, this Warrant
shall, after any such event, entitle the Holder to receive upon exercise the
number of shares of Stock or other securities or property (including cash) of
the Person (if applicable) resulting from such event, which the holder of
securities deliverable upon exercise of this Warrant (at the time of such event)
would have been entitled to receive upon such event; and in any such case the
provisions of Section 4 with respect to the rights and interests thereafter of
the holders of this Warrant shall be appropriately adjusted so as to be
applicable, as nearly as practicable, to any shares of Stock or other securities
or any property (including cash) thereafter deliverable upon exercise of this
Warrant. The Person resulting from such sale or consolidation or surviving such
merger or to which such sale shall be made shall execute and deliver to the
Holder a supplemental agreement as provided in Section 6.5 below. Any adjustment
pursuant to this Section 4.3 which shall be approved in good faith by the Board
of Directors of the Company pursuant to a resolution delivered to the Holder
shall be conclusive for all purposes hereof. For the purposes of this Agreement
"person" means any individual, partnership, firm, corporation, limited liability
company or partnership, association, trust, unincorporated organization or other
entity, as well as any syndicate or group that would be deemed to be a person
under Section 13(d)(3) of the Securities Exchange Act of 1934, as amended.

     4.4 Other Distributions. In case the Company shall distribute to all
holders of its shares of Common Stock shares of Stock other than Common Stock or
evidences of its indebtedness or assets (excluding cash dividends or
distributions payable out of consolidated earnings or retained earnings and
dividends or distributions referred to in Section 4.1 above) or rights, options,
warrants or convertible or exchangeable securities containing the right to
subscribe for or purchase shares of Common Stock (excluding those referred to in
Section 4.2 above), then in each case the Number of Shares thereafter
purchasable upon the exercise of this Warrant shall be determined by multiplying
the Number of Shares theretofore purchasable upon the exercise of this Warrant,
by a fraction of which the numerator shall be the Current Market Price per share
of Common Stock on the record date mentioned below in this Section 4.4 plus the
then fair value (as reasonably determined by the Board of Directors of the
Company in good faith, whose determination shall be conclusive absent manifest
error, irrespective of the accounting treatment thereof) of the portion of the
shares of Stock other than Common Stock or assets or evidences of indebtedness
so distributed or of such subscription rights, options or warrants, or of such
convertible or exchangeable securities applicable to one share of Common Stock,
and of which the denominator shall be the Current Market Price per share of
Common Stock on such record date. Such adjustment shall be made whenever any
such distribution is made, and shall become effective immediately after the
record date for the determination of Stockholders entitled to receive such
distribution.

     4.5 Additional Adjustment of Purchase Price. Whenever the Number of Shares
purchasable upon the exercise of this Warrant is adjusted, as provided herein,
the Purchase Price payable upon exercise of this Warrant shall be adjusted by
multiplying such Purchase Price immediately prior to such adjustment by a
fraction, of which the numerator shall be the Number of Shares purchasable upon
the exercise of this Warrant immediately prior to such adjustment, and of which
the denominator shall be the Number of Shares so purchasable immediately
thereafter.

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     4.6 No De Minimis Adjustments. No adjustment in the Purchase Price shall be
required unless such adjustment would require an increase or decrease of at
least 1% in such price; provided, however, that any adjustments which by reason
of this Section 4.6 are not required to be made shall be carried forward and
taken into account in any subsequent adjustment. All calculations under this
Section 4.6 shall be made to the nearest one-twentieth of a cent or to the
nearest one-hundredth of a share, as the case may be.

     4.7 Treasury Shares. For the purpose of Section 4, shares of Common Stock
or other securities held in the treasury of the Company shall not be deemed to
be outstanding, and the sale or other deposition of any shares of Common Stock
or other securities held in the treasury of the Company shall be deemed an
issuance thereof.

     4.8 Corporate Action. Before taking any action which would cause an
adjustment reducing the Purchase Price below the then par value, if any, of the
shares of Common Stock issuable upon exercise of this Warrant, the Company shall
take any corporate action which may, in the opinion of its counsel, be necessary
in order that the Company may validly and legally issue fully paid and
nonassessable shares of Common Stock at such adjusted Purchase Price.

     4.9 Independent Public Accountants. The certificate of a "Big Five" firm of
independent public accountants selected by the Board of Directors of the Company
shall be conclusive evidence of the correctness of any computation made under
Section 4.

     4.10 Notice of Certain Events. In case at any time prior to the expiration
date of this Warrant:

          (i) the Company shall declare a dividend (or any other distribution)
     on the Common Stock (other than a dividend in cash out of retained
     earnings); or

          (ii) the Company shall authorize the granting to the holders of Common
     Stock of rights or warrants to subscribe for or purchase any shares of
     stock of any class or of any other rights; or

          (iii) there shall be any reclassification of the Common Stock of the
     Company (other than a subdivision or combination of its outstanding Common
     Stock); or

          (iv) there shall be any capital reorganization by the Company; or

          (v) there shall be a consolidation or merger involving the Company or
     sale of all or substantially all of the Company's property and assets
     (except a merger or other reorganization in which the Company shall be the
     surviving corporation or a consolidation, merger or sale with a
     wholly-owned subsidiary); or

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          (vi) there shall be voluntary or involuntary dissolution, liquidation
     and winding up by the Company or dividend or distribution to holders of
     Common Stock (other than the customary cash and stock dividends); or

          (vii) any other action shall occur which would give rise to an
     adjustment to the Purchase Price or the Number of Shares hereunder, then in
     any one or more of said cases, the Company shall cause to be delivered to
     the Holder, at the earliest practicable time (and, in any event, not less
     than 25 days before any record date or other date set for definitive
     action), notice of the date on which the books of the Company shall close
     or a record shall be taken for such dividend, distribution or subscription
     rights or such reorganization, sale, consolidation, merger, dissolution,
     liquidation or winding up shall take place, as the case may be. Such notice
     shall also set forth such facts as shall indicate the effect of such action
     (to the extent such effect may be known at the date of such notice) on the
     Purchase Price and the kind and amount of the shares of stock and other
     securities and property deliverable upon exercise of this Warrant. Such
     notice shall also specify the date, if known, as of which the holders of
     record of the Common Stock shall participate in said dividend, distribution
     or subscription rights or shall be entitled to exchange their shares of the
     Common Stock for securities or other property (including cash) deliverable
     upon such reorganization, sale, consolidation, merger, dissolution,
     liquidation or winding up, as the case may be (on which date, in the event
     of voluntary or involuntary dissolution, liquidation, or winding up of the
     Company, other than dissolution, liquidation or winding up following a
     consolidation or merger of the Company with or into, or sale of
     substantially all of its assets to, another corporation, the rights to
     exercise this Warrant shall terminate).

     4.11 Other Securities Adjustments. If as a result of Section 4, a Holder is
entitled to receive any securities other than Common Stock upon exercise of this
Warrant, the number and purchase price of such securities shall thereafter be
adjusted from time to time in the same manner as provided pursuant to Section 4
for Common Stock. The allocation of purchase price between various securities
shall be made in writing by the Board of Directors of the Company in good faith
at the time of the event by which the holder became entitled to receive new
securities, and a copy sent to the Holder.

     4.12 Notices of Adjustments. When any adjustment is required to be made
under Section 4, the Company shall promptly (a) determine such adjustments, (b)
prepare and retain on file a statement describing in reasonable detail the
method used in arriving at the adjustment; and (c) cause a copy of such
statement, together with any agreement required by Section 6.5, to be mailed to
the Holder within 10 days after the date on which the circumstances giving rise
to such adjustment occurred.

     4.13 Computations and Adjustments. Upon each computation of an adjustment
under this Section 4, the Purchase Price shall be computed to the nearest cent
and the Number of Shares shall be calculated to the next highest whole share.
However, the fractional amount shall be used in calculating any future
adjustments. No fractional shares of Common Stock shall be issued in connection
with the exercise of this Warrant, but the Company shall, in the case of the
final

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exercise under this Warrant, make a cash payment for any fractional shares based
on the Current Market Price of the Common Stock on the date of exercise.
Notwithstanding any changes in the Purchase Price or the Number of Shares, this
Warrant, and any Warrants issued in replacement or upon transfer thereof, may
continue to state the initial Purchase Price and the Number of Shares.
Alternatively, the Company may elect to issue a new Warrant or Warrants of like
tenor for the additional shares of Common Stock purchasable hereunder or, upon
surrender of the existing Warrant, to issue a replacement Warrant evidencing all
the Warrants to which the Holder is entitled after such adjustments.

     4.14 Exercise Before Payment Date. In the event that this Warrant is
exercised after the record date for any event requiring an adjustment, but prior
to the actual event, the Company may elect to defer payment of the adjusted
amount to the Holder until the actual event occurs; provided, however, that the
Company shall deliver a due bill or other appropriate instrument to the Holder
transferable to the same extent as the other securities issuable on exercise
evidencing the Holder's right to receive such additional amount upon the
occurrence of the event requiring such adjustment.

     4.15 Current Market Price. "Current Market Price" for the Common Stock on
any given date means (a) the closing price on the previous trading day for the
Common Stock on the principal stock exchange on which the Common Stock is traded
(or, in the case of issuances of stock options with an exercise price equal to
fair market value on the date of grant pursuant to the terms of a plan, such
date) or (b) if not so traded, the closing price (or, if no closing price is
available, the average of the bid and asked prices) for such date on the NASDAQ
if the Common Stock is listed on the NASDAQ or (c) if not listed on any exchange
or quoted on the NASDAQ, such value as may be determined in good faith by the
Company's Board of Directors, which determination shall be conclusively binding
on the parties.

5.   Redemption.

     5.1 Redemption at Company's Option. The Company may, upon 30 days prior
written notice (the "Redemption Notice") to the Holder, redeem all, but not less
than all of the Warrants granted hereunder that have not been exercised before
the date referred to in Section 5.2(d) at a redemption price of $0.05 per
Warrant (the "Redemption Price"), so long as the Current Market Price (as
defined in Section 4.15(a) and (b) above) is greater than the following prices
(the "Target Prices") for any period of 20 consecutive trading days preceding
the date the Redemption Notice is given:

                     TIME PERIOD                          TARGET PRICE
                     -----------                          ------------

         August 4, 1999-- August 4, 2000                     $12.10

         August 5, 2000-- August 4, 2001                     $14.52

         August 5, 2001-- August 4, 2002                     $17.42

         August 5, 2002-- August 4, 2003                     $20.90


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     The date fixed for redemption of this Warrant is referred to herein as the
"Redemption Date."

     5.2 Redemption Notice. The Redemption Notice shall specify (a) the
Redemption Price, (b) the Redemption Date, (c) the place where this Warrant
shall be delivered and the Redemption Price paid, and (d) that the right to
exercise the Warrant shall terminate at 5:00 p.m. (Minneapolis time) on the
business day immediately preceding the Redemption Date. No failure to mail such
notice nor any defect therein or in the mailing thereof shall affect the
validity of the proceedings for such redemption except as to a Holder (I) to
whom notice was not mailed (ii) whose notice was defective.

     5.3 Failure to Exercise. Any right to exercise this Warrant shall terminate
at 5:00 p.m. (Minneapolis time) on the business day immediately preceding the
Redemption Date. On and after the Redemption Date, the Holder shall have no
further rights except to receive, upon surrender of this Warrant, the Redemption
Price.

     5.4 Surrender of Warrant. From and after the Redemption Date, the Company
shall, at the place specified in the Redemption Notice, upon presentation and
surrender to the Company by or on behalf of the Holder of the Warrant to be
redeemed, deliver or cause to be delivered to or upon the written order of the
Holder a sum in cash equal to the Redemption Price of this Warrant. From and
after the Redemption Date and upon the deposit or setting aside by the Company
of a sum sufficient to redeem this Warrant, it shall expire and become void and
all rights hereunder, except the right to receive payment of the Redemption
Price, shall cease.

     5.5 Adjustments. If the shares of Common Stock are subdivided or combined
into a greater or smaller number of shares of Common Stock, the Target Prices
shall be proportionally adjusted by the ratio which the total number of shares
of Common Stock outstanding immediately prior to such event bears to the total
number of shares of Common Stock to be outstanding immediately after such event.

6.   Covenants. The Company agrees that:

     6.1 Reservation of Stock. During the period in which this Warrant may be
exercised, the Company will reserve sufficient authorized but unissued
securities to enable it to satisfy its obligations on exercise of this Warrant
and shall use its reasonable best efforts to cause all shares of Common Stock
issued upon the exercise of this Warrant to be listed on any exchanges on which
the Common Stock is then listed. If at any time the Company's authorized
securities shall not be sufficient to allow the exercise of this Warrant, the
Company shall take such corporate action as may be necessary to increase its
authorized but unissued securities to be sufficient for such purpose;

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     6.2 No Liens, etc. All securities that may be issued upon exercise of this
Warrant will, upon issuance, be validly issued, fully paid, nonassessable and
free from all taxes, liens and charges with respect to the issue thereof, and
shall be listed on any exchanges on which that class of securities is listed;

     6.3 Furnish Information. During the term of this Warrant, the Company will
promptly deliver to the Holder copies of all financial statements, reports and
proxy statements which the Company shall have sent to its stockholders
generally;

     6.4 Stock and Warrant Transfer Books. Except upon dissolution, liquidation
or winding up or for ordinary holidays and weekends, the Company will not at any
time close its stock or warrant transfer books so as to result in preventing or
delaying the exercise or transfer of this Warrant; and

     6.5 Merger; Consolidation or Sale of Assets of the Company. Except in the
case of a merger or consolidation where the consideration is payable entirely in
cash or obligations, the Company will not merge or consolidate with or into any
Person, or sell or otherwise transfer its property, assets and business
substantially as an entirety to a successor Person, unless the Person resulting
from such merger or consolidation (if not the Company), or such successor
Person, shall expressly assume, by supplemental agreement reasonably
satisfactory in form to the then Majority Holders (as defined below) and
executed and delivered to the Holder, the due and punctual performance and
observance of each and every covenant and condition of this Agreement to be
performed and observed by the Company. "Majority Holders", as of any date, shall
mean the holders of this Warrant (or replacement warrants issued pursuant
hereto) and of the substantially similar warrants issued contemporaneously
herewith pursuant to the Common Stock Purchase Agreement (or replacement
warrants issued pursuant thereto) who together have rights to exercise such
warrants for a majority of the Warrant Shares (as defined in the Common Stock
Purchase Agreement).

7.   Status of Holder.

     7.1 Not a Stockholder. Unless the Holder exercises this Warrant in writing,
the Holder shall not be entitled to any rights (a) as a stockholder of the
Company with respect to the shares as to which the Warrant is exercisable
including, without limitation, the right to vote or receive dividends or other
distributions, or (b) to receive any notice of any proceedings of the Company
except as otherwise provided in this Warrant.

     7.2 Limitation of Liability. Unless the Holder exercises this Warrant in
writing, the Holder's rights and privileges hereunder shall not give rise to any
liability for the Purchase Price or as a stockholder of the Company, whether to
the Company or its creditors.

8. Registration Rights. The shares purchasable upon exercisable of this Warrant
shall be Registerable Securities as defined in Section 10.1 of the Common Stock
Purchase Agreement.

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9.   General Provisions.

     9.1 Complete Agreement; Modifications. This Warrant and any documents
referred to herein or executed contemporaneously herewith constitute the
parties' entire agreement with respect to the subject matter hereof and
supersede all agreements, representations, warranties, statements, promises and
understandings, whether oral or written, with respect to the subject matter
hereof. The Warrant may not be amended, altered or modified except by a writing
signed by the parties.

     9.2 Cooperation. Each party hereto agrees to execute any and all further
documents and writings and to perform such other reasonable actions which may be
or become necessary or expedient to effectuate and carry out this Warrant.

     9.3 Notices. All notices under this Warrant shall be in writing and shall
be delivered by personal service or telecopy or certified mail return receipt
requested (if such service is not available, then by first class mail), postage
prepaid, to such address as may be designated from time to time by the relevant
party, and which shall initially be:

     (a) If to the Company:

              Diametrics Medical, Inc.
              2658 Patton Road
              Roseville, Minnesota 55113
              Attention:  Chief Financial Officer
              Telecopy:  (612) 639-8459

              With a copy to:
              Dorsey & Whitney LLP
              Pillsbury Center South
              220 South Sixth Street
              Minneapolis, Minnesota 55402
              Attention:  Kenneth Cutler
              Telecopy:  (612) 340-8738

     (b) If to the Holder:

              Hewlett-Packard Company
              3000 Hanover Street, Mail Stop 20BT
              Palo Alto, California 94304
              Attention: Director, Corporate Development
              Phone: (650) 857-1501
              Fax: (650) 852-8342

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<PAGE>

              With a copy to:
              Hewlett-Packard Company
              3000 Hanover Street, Mail Stop BQ
              Palo Alto, California 94304
              Attention: General Counsel
              Phone: (650) 857-1501
              Fax: (650) 857-4392

         Any notice sent by certified mail shall be deemed to have been given
three days after the date on which it is mailed. All other notices shall be
deemed given when received. No objection may be made to the manner of delivery
of any notice actually received in writing by an authorized agent of a party.

     9.4 No Third-Party Benefits; Successors and Assigns. None of the provisions
of this Warrant shall be for the benefit of, or enforceable by, any third-party
beneficiary. Except as provided herein to the contrary, this Warrant shall be
binding upon and inure to the benefit of the parties, their respective
successors and permitted assigns.

     9.5 Governing Law. This Warrant concerns a Minnesota corporation, and all
questions with respect to the Warrant and the rights and liabilities of the
parties will be governed by the laws of Minnesota regardless of the choice of
law provisions of Minnesota or any other jurisdiction.

     9.6 Waivers Strictly Construed. With regard to any power, remedy or right
provided herein or otherwise available to any party hereunder (a) no waiver or
extension of time shall be effective unless expressly contained in a writing
signed by the waiving party; and (b) no alteration, modification or impairment
shall be implied by reason of any previous waiver, extension of time, delay or
omission in exercise, or other indulgence.

     9.7 Severability. The validity, legality or enforceability of the remainder
of this Warrant shall not be affected even if one or more of its provisions
shall be held to be invalid, illegal or unenforceable in any respect.


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     9.8 Attorneys' Fees. Should any litigation or arbitration be commenced
(including any proceedings in a bankruptcy court) between the parties hereto or
their representatives concerning any provisions of this Warrant or the rights
and duties of any person or entity hereunder the party or parties prevailing in
such proceeding shall be entitled, in addition to such other relief as may be
granted, to the attorneys' fees and court costs incurred by reason of such
litigation.

     IN WITNESS WHEREOF, the Company has caused this Warrant to be duly executed
effective as of June 28, 1999.

                                       DIAMETRICS MEDICAL, INC.

                                       By:        /s/ Laurence L. Betterley
                                              ---------------------------------
                                       Title: Senior Vice President and
                                              Chief Financial Officer
                                              ---------------------------------

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                                 ASSIGNMENT FORM

     FOR VALUE RECEIVED, __________________________________ hereby sells,
assigns and transfers to the transferee named below the rights to purchase
______________ of the Number of Shares under this Warrant, together with all
rights, title and interest therein. The rights to purchase the remaining Number
of Shares shall remain the property of the undersigned.

     Dated: _____________________

                                       [NAME OF HOLDER]

                                       By_________________________________

                                       Name ______________________________
                                                   (Please Print)

                                           Address:_______________________
                                                   _______________________
                                                   _______________________

Employer Identification Number, Social
Security Number or other identifying
number:

______________________________________


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                                  EXERCISE FORM

                     To Be Executed Upon Exercise Of Warrant

     The undersigned hereby exercises the Warrant with regard to ___________
shares of Common Stock and herewith makes payment of the purchase price in full.
The undersigned requests that certificate(s) for such shares and the Warrant for
any unexercised portion of this Warrant be issued to the Holder.

     Dated:_______________________________

                                       [NAME OF HOLDER]

                                       By_________________________________

                                       Name ______________________________
                                                  (Please Print)

                                           Address:_______________________
                                                   _______________________
                                                   _______________________

Employer Identification Number, Social
Security Number or other identifying
number:

______________________________________

                                      14
