<PAGE>

          This Exchange Offer Expires at 5:00 p.m., New York City time,
                             on February 28, 2001.


                              LETTER OF ACCEPTANCE

                                       OF


                   -------------------------------------------
                                [Name of Holder]


         DELIVERED PURSUANT TO THE EXCHANGE OFFER DATED FEBRUARY 8, 2001

                                       OF

                             DATAMETRICS CORPORATION


         IMPORTANT: IN ORDER TO PARTICIPATE IN THE EXCHANGE OFFER YOU MUST
         COMPLETE AND SIGN THIS LETTER OF ACCEPTANCE AND SEND OR DELIVER IT AND
         YOUR 12% SECURED NOTE TO DATAMETRICS CORPORATION. PLEASE READ CAREFULLY
         THE INSTRUCTIONS ACCOMPANYING THIS LETTER OF ACCEPTANCE REGARDING
         EXECUTION AND DELIVERY OF THIS LETTER OF ACCEPTANCE. AN IMPROPERLY
         COMPLETED LETTER OF ACCEPTANCE COULD PREJUDICE YOUR RIGHTS UNDER THE
         EXCHANGE OFFER.


NO HOLDER IS REQUIRED TO TENDER HIS 12% SECURED NOTE. PARTIAL TENDERS OF A 12%
SECURED NOTE WILL NOT BE ACCEPTED. A HOLDER MAY DECIDE, AFTER CONSULTATION WITH
HIS COUNSEL, ACCOUNTANT OR OTHER ADVISOR, THAT IT IS NOT IN HIS BEST INTEREST TO
TENDER HIS 12% SECURED NOTE. THIS IS A DECISION WHICH EACH HOLDER MOST MAKE AND
DATAMETRICS CORPORATION DOES NOT EXPRESS ANY OPINION CONCERNING THE CHOICE TO BE
MADE BY ANY HOLDER.


Gentlemen:

         The undersigned hereby tenders to Datametrics Corporation (the
"Corporation") his 12% Secured Note in the principal amount of $___________ in
exchange for ____ shares of Common Stock, par value $.01 per share (the "Common
Stock"), all upon the terms and conditions set forth in the Exchange Offering
Statement dated February 8, 2001, receipt of which is hereby acknowledged, and
executes and delivers this Letter of Acceptance (which together with the
Exchange Offering Statement constitutes the "Exchange Offer") in evidence
thereof.

         Subject only to the delivery of the Common Stock in accordance with the
Exchange Offer, the undersigned hereby sells, assigns and transfers to the
Corporation all right, title and interest in the 12% Secured Note tendered
pursuant to the Exchange Offer and the Corporation shall receive all benefits
and otherwise exercise all rights of beneficial ownership of such 12% Secured
Note, all in accordance with the terms of the Exchange Offer. In particular, the
undersigned hereby confirms that by tendering the 12% Secured Note in exchange
for Common Stock, the undersigned is irrevocably waiving any right to receive
payment of the principal amount of, and any accrued or unaccrued interest on,
and any other amounts owing in respect of, the 12% Secured Note so tendered and
irrevocably releases any claims for any amounts resulting from any defaults
under the 12% Secured Note, including, without limitation, all claims for
damages, including, without limitation, liquidated damages, for any such
defaults under the 12% Secured Note or related documents including, without
limitation, any damages for any failure to comply with any registration
requirements imposed on the Corporation under any Registration Rights Agreement
or otherwise.



<PAGE>



         The undersigned understands that under the circumstances set forth in
the Exchange Offering Statement and this Letter of Acceptance the Corporation
may not be required to accept the 12% Note tendered hereby.

         The undersigned understands that the Common Stock has not been
registered under the Securities Act of 1933, as amended (the "Securities Act"),
in reliance on an exemption thereunder for, inter alia, transactions involving
offers and sales to existing security holders, that the Common Stock has not
been approved or disapproved by the Securities and Exchange Commission or by any
other federal or state commission or agency, and that no such commission or
agency has passed on the accuracy or adequacy of the Exchange Offering
Statement.

         Simultaneously with the delivery of this Letter of Acceptance, the
undersigned in executing and delivering an Investor Suitability Questionnaire
pursuant to which the undersigned is establishing his accredited status under
Regulation D under the Securities Act.

         The undersigned represents that the undersigned is acquiring the Common
Stock for the undersigned's own account, for investment purposes only, and not
with a view to the sale or other distribution thereof, in whole or in part.

         The undersigned understands that the Common Stock issued in the
Exchange Offer may not be sold, transferred, hypothecated or otherwise disposed
of unless registered under the Securities Act and the relevant state securities
laws or pursuant to an applicable exemption therefrom. The undersigned further
understands that there is no obligation on the part of the Corporation so to
register the Common Stock to facilitate the sale thereof by the undersigned and
that the Corporation has no intention to do so.

         The undersigned hereby warrants that the undersigned has full authority
to sell, assign and transfer the 12% Note tendered herewith, that all of the
information set herein is true and correct and that the Corporation will acquire
good and unencumbered title to such 12% Secured Note, free and clear of all
liens, charges, encumbrances and adverse claims, when the same is acquired by it
accordance with the terms of the Exchange Offer. All warranties herein contained
shall survive consummation of the transaction contemplated herewith. All
authority herein conferred or agreed to be conferred shall survive the death or
incapacity of the undersigned, and all obligations of the undersigned hereunder
shall be binding upon the heirs, personal representatives, successors and
assigns of the undersigned.

         Unless otherwise indicated below under "Special Delivery Instructions,"
please mail the Common Stock to the undersigned at the address below the
undersigned's signature.


                  ALL TENDERING HOLDERS MUST DATE AND SIGN HERE


 ...............................................................................
                                  (PLEASE DATE)

         X.....................................................................

         X.....................................................................
                            SIGNATURE(S) OF OWNER(S)

         Address:..............................................................
                                    (NUMBER)                  (STREET)

 ...............................................................................
         (CITY)                      (STATE)                (ZIP CODE)





<PAGE>



                          SPECIAL DELIVERY INSTRUCTIONS


                  To be competed ONLY if the Common Stock is to be issued in the
         name of the undersigned but sent to someone other than the undersigned
         or to the undersigned at an address other than that shown below the
         undersigned's signature.

         Please mail to:


         Name:.................................................................
                             (PLEASE TYPE OR PRINT)

         Address:..............................................................

         ......................................................................
                               (INCLUDE ZIP CODE)


                  If signature is by a trustee, executor, administrator,
         guardian, attorney-in-fact, officer of a corporation or other person
         acting in a fiduciary or representative capacity, full title must be
         set forth, and a copy of any document or instrument authorizing such
         person to act in such capacity must be supplied herewith.

         Name:.................................................................
                             (PLEASE TYPE OR PRINT)

         Address:..............................................................
                                    (NUMBER)                         (STREET)

 ...............................................................................
         (CITY)                      (STATE)                        (ZIP CODE)



                                  INSTRUCTIONS


         The tender of your 12% Secured Note can be made by completing the
Letter of Acceptance and returning it and your 12% Secured Note to the
Corporation. PLEASE FOLLOW THESE INSTRUCTIONS CAREFULLY. If you have any
questions on any aspect of this transaction, whether procedural or substantive,
Mr. Gary Herman (212-603-7557) will be pleased to assist you. You should feel
free to call Mr. Herman, collect, at any time.

                                  TIME SCHEDULE

         Please bear in mind that the Exchange Offer will terminate at 5:00
p.m., New York City time, on February 28, 2001. If you wish to avail yourself of
the Exchange Offer, please submit your Letter of Acceptance as early as
possible. Any Letter of Acceptance received after the Expiration Time may not be
accepted by the Corporation. You may withdraw your tender of a 12% Secured Note
at any time prior to the Expiration Time, by written notice of withdrawal to the
Corporation.

                             PROCEDURE FOR TENDERING

         1. LETTER OF ACCEPTANCE. You may tender your 12% Secured Note by
completing and executing the Letter of Acceptance, and returning the Letter of
Acceptance and your 12% Secured Note to the Corporation.



                                       3
<PAGE>



         2. DELIVERY. You should deliver your Letter of Acceptance and your 12%
Secured Note, either by registered or certified mail or by hand or by Federal
Express (using account number 248143231), to:

                     Datametrics Corporation
                     c/o Mr. Gary Herman
                     1325 Avenue of the Americas, 26th Floor
                     New York, New York 10019

         3. TIME OF DELIVERY. 12% Secured Notes may be tendered at any time
prior to the Expiration Time, which is 5:00 p.m., New York City time, on
February 28, 2001. The Corporation must receive your Letter of Acceptance and
your 12% Secured Note by the Expiration Time.

         4. METHOD OF DELIVERY. You may deliver your Letter of Acceptance and
your 12% Secured Note to the Corporation by mail or by hand as described in
instruction no. 2. The method of delivery is at your election and risk. If you
choose to deliver by mail, then registered or certified mail, with return
receipt requested, is recommended. If time will not permit your signed documents
to reach the Corporation prior to the Expiration Time, your tender may be
effected if (a) prior to the Expiration Time, the Corporation has received a
telegram, telex, facsimile transmission or letter from you or your authorized
agent setting forth your name and a statement that a tender is being made
pursuant to the Exchange Offer and (b) your properly executed Letter of
Acceptance and your 12% Secured Note are received by the Corporation within two
business days after the Expiration Time.

         5. PROPER TENDER ACCEPTANCE. 12% Secured Notes are properly tendered
pursuant to the Exchange Offer only when a duly executed Letter of Acceptance
and the 12% Secured Note are received by the Corporation, or when a telegram,
telex, facsimile transmission or letter is received, followed by receipt of the
signed Letter of Acceptance and the 12% Secured Note as provided above. All
questions as to the validity, eligibility (including time of receipt) and
acceptance of your tender of a 12% Secured Note will be determined by the
Corporation whose determination will be final and binding. The Corporation
reserves the absolute right to reject any and all tenders of 12% Secured Notes
not in proper form or if the acceptance thereof or payment therefor would, in
the opinion of counsel for the Corporation, be unlawful or not in accordance
with any rules or regulations to which the Corporation may be subject at the
time the Corporation will not be under a duty to notify you or your agent or
advisor of any defects or irregularities in your tender nor will the Corporation
incur any liability for failure to give any such notification. The Corporation
also reserves the absolute right to waive any and all conditions of the Exchange
Offer or any defect in your tender.