Document:

SHARE PURCHASE AGREEMENT

     THIS SHARE PURCHASE AGREEMENT, made and entered into as of this 17th day of
October, 1991 ("Agreement"), by and between J. BUCK DOWDY ("Seller") , being the
holder  of  all  of  the  outstanding   shares  of  capital  stock  of  OPTICHEM
TECHNOLOGIES, INC., a North Carolina corporation ("Optichem"), and ENVIROMETRICS
DEVELOPMENT CO., INC., a South Carolina corporation ("Purchaser" or "EDC") .

     WHEREAS,  Seller  desires to sell to  Purchaser  and  Purchaser  desires to
purchase from Seller all of the shares of outstanding capital stock of Optichem,
being all the outstanding shares of all classes of common or preferred stock for
valuable consideration and upon the terms and conditions hereinafter set forth;

     NOW THEREFORE,  in consideration of the promises,  payments,  covenants and
agreements hereinafter stipulated to be made, kept and performed, it is mutually
understood and agreed by and between the parties as follows:

     1. Sale and Purchase of Stock.  Seller  hereby  agrees to sell to Purchaser
and Purchaser agrees to purchase from Seller all of the aforementioned shares of
voting and nonvoting common stock of Optichem and Purchaser shall pay Seller for
the shares of stock as provided in this Agreement.

     2.  Effective  Date of  Transfer.  The stock  transferred  pursuant to this
Agreement shall be transferred effective the date of closing and upon receipt of
the stock certificates by purchaser, purchaser shall have all rights to vote the
stock and all dividend  distribution and liquidation  rights as a shareholder of
Optichem.

     3. Purchase  Price.  The purchase  price of the shares of stock shall be an
amount not to exceed one  hundred  thousand  and  no/100  ($100,000.00)  dollars
payable on the terms and conditions set forth below.

     4. Payment of Purchase Price.  Purchaser will pay Seller the purchase price
in quarterly  payments  based on five percent (5%) of net sales of products sold
by  Optichem,  Purchaser  or a Related  Party of either (as that term is defined
herein) , which are developed or manufactured  utilizing the technology licensed
pursuant to that  certain  License  Agreement  dated  December  16, 1986 between
Optichem  and  Perfect  View,  Inc.,  a  North  Carolina  corporation  ("License
Agreement").  It is  understood  by all parties that  Optichem  will be the sole
manufacturer  of the products.  The quarterly  payments from Purchaser to Seller
shall be made within thirty (30) days of the end of each calendar  quarter based
on the net sales of that quarter.  For example,  the first  payment  pursuant to
this Section  will be made no later than July 30,  1992,  based on the sales for
the calendar  quarter  ending June 30,  1992.  Payments  will only be made,  and
Purchaser will only be obligated to make payments as long as Optichem, Purchaser
or a Related  Party of either is selling  the  product.  If for any reason  such
sales cease,  the quarterly  payments will also cease and Purchaser  will not be
obligated  to make any  further  payments  unless and until  sales by  Optichem,
Purchaser or a Related  Party of either  resume.  For purposes of this  Section,
sales shall include sales by Purchaser,  Optichem or any party who is a "Related
Person"  to  Purchaser  or  Optichem  within the  meaning of Section  267 of the
Internal Revenue Code of 1986, as amended  (collectively  "Related Party") . Net
sales shall be defined as gross sales of Purchaser,  Optichem or a Related Party
to its third-party customers, less any discounts, allowances, or returns.

     5. Access to Sales  Records.  With the quarterly  payment,  Purchaser  will
provide the necessary financial  information to Seller and Seller shall have the
right to inspect the sales records of Optichem,  Purchaser or any Related Party,
upon  reasonable  notice to  Purchaser,  to evidence the amount of the quarterly
payment.  In the event Seller  disputes the amount of the quarterly  payment and
the  parties  are  unable to  resolve  the  dispute  themselves,  the Seller and
Purchaser  mutually agree and understand that the accounting firm of McGladrey &
Pullen  will  perform an audit of all net sales by  Purchaser  for the  monitors
discussed  herein and the results will determine the quarterly  payment.  In the
event the  accounting  firm is  retained,  the expenses  will be shared  equally
between the Seller and Purchaser and  Purchaser may deduct  Seller's  portion of
the expenses from the quarterly payment.

     6.  Transfer of Shares.  Upon  execution  of this  Agreement,  Seller shall
deliver,  assign and transfer all share  certificates  representing  outstanding
shares of common  stock in  Optichem,  said  certificates  being  duly  endorsed
without  restriction  or  encumbrance  to Purchaser.  With delivery of the share
certificates,  Seller  shall also deliver to Purchaser  all  corporate  records,
minutes, resolution, and financial statements.

     7.  Representations  and  Warranties of Seller.  Seller hereby  represents,
warrants, covenants and agrees that:

     (a)  Optichem is a  corporation  duly  organized  and  existing and in good
standing under the laws of the State of North Carolina.

     (b) The entire  authorized  capital  stock of  Optichem  consists of 80,000
shares of Class A voting  Common  Stock and 20,000  shares of Class B  nonvoting
Common Stock, both with a par value of $1.00 per share;

     (c) all financial statements, whether audited or unaudited, lists of assets
and  liabilities  and all  corporate  records  and  other  documents  previously
delivered to EDC by Seller,  (i) are true,  correct and complete in all material
respects  and (ii) fairly  present the  financial  condition of Optichem on such
balance  sheet  dates and the  results of the  operations  of  Optichem  for the
periods  covered by such  statements.  The  charges,  accruals,  and reserves on
Optichem's books in respect of taxes for all periods to date are, in the opinion
of Seller,  adequate,  and they do not anticipate any additional assessments for
any of such periods.

     (d) Except as otherwise disclosed in Exhibit A (which shall be prepared and
dated as of the  Closing  Date,  notwithstanding  the  date of this  Agreement);
Optichem has no liabilities, contingent or otherwise and is not in default under
any  contracts,   including  loan  agreement  provisions;  it  has  no  material
obligation or liability,  contingent,  anticipated  or otherwise;  no claims for
federal  or state  taxes are  pending  against  it and it has no  obligation  or
liability  for  federal  or  state  taxes;  and  Optichem  is not a party in any
litigation  or  administrative  proceeding  which  would  adversely  affect  its
financial condition or its operations,  nor is any such litigation or proceeding
threatened.

     (e) Optichem is a Subchapter S corporation  for federal income tax purposes
and no events have occurred and no actions have been taken that would  terminate
its S corporation status prior to the closing  hereunder;  and that Optichem and
its  shareholders  will maintain the S corporation  status of Optichem until the
closing.  Seller agrees to execute and to cause  Optichem to execute an Election
to Close Books Upon S Corporation  Termination and Consent of  Shareholders,  in
the form attached  hereto as Exhibit B, with respect to the termination of the S
corporation  status of Optichem that will be caused by the purchase of its stock
by Purchaser. Seller agree to pay all federal and state income taxes relating to
the  operations  of Optichem  for the period from January 1, 1989 to the closing
hereunder,  and shall  indemnify  and hold harmless EDC from and against any tax
liability  attributable  to the  operations  of  Optichem  prior  to the date of
closing.

     (f) Optichem has such valid franchises,  licenses and/or permits, free from
unreasonably burdensome restrictions,  as are necessary to carry on its business
as the  same is being  conducted  and to own or hold the  properties  or  assets
owned, held or operated by it.

     (g) Seller is the owner of record of all of the  outstanding  capital stock
of  Optichem,  have full right to sell said  stock,  and upon sale and  transfer
thereof to EDC pursuant hereto and payment of the purchase price  therefor,  EDC
shall  acquire  good  title to said  stock  free and clear of all  restrictions,
liens, encumbrances and other adverse claims.

     (h) Except as  disclosed  in  writing to EDC prior to the date of  closing,
Optichem has no long-term  agreements with either  individuals or  corporations,
leases,  employment  agreements,  deferred  compensation plans, pension plans or
profit-sharing plans.

     (i) Seller represents that there are no outstanding  unresolved discussions
or  negotiations  with or offers  from or  contracts  with any other  company or
person for the purchase or acquisition of securities or assets of Optichem.

     (j) This Agreement  constitutes a valid and legally  binding  obligation of
Seller enforceable in accordance with its terms.

     (k) Seller  and/or  Optichem,  as of the date of this  Agreement,  have not
taken any action or executed  any  documents  which would  negate the  potential
validity  and  enforceability  of the License  Agreement  held by  Optichem  and
described in this  Agreement.  Seller  further  agrees not to take any action or
cause any action to be taken which would affect the  validity or  enforceability
of the License  Agreement and agrees to cooperate  fully with  Purchaser  and/or
Optichem  in the  defense  of any  claim or action  affecting  the  validity  or
enforceability  of the License  Agreement.  Purchaser will reimburse  Seller for
reasonable costs and expenses incurred in cooperating with Purchaser/Optichem in
the defense of any litigation.  Notwithstanding  the foregoing,  Seller makes no
representation  or warranty as to the validity or  enforceability of the License
Agreement.

     8. Representations and Warranties of Purchaser. Purchaser hereby represents
and warrants that:

     (a) EDC is a corporation  duly  organized and existing and in good standing
under the laws of the State of South Carolina and has full  corporate  power and
authority to acquire the capital stock of Optichem as herein contemplated.

     (b) This Agreement  constitutes a valid and legally  binding  obligation of
EDC  enforceable  in  accordance  with its terms,  and  approved by the Board of
Directors of EDC prior to the closing, as evidenced by the Corporate  Resolution
attached as Exhibit C and incorporated herein by reference.

     (c)  Purchaser  understands  that  the  stock  purchased  pursuant  to this
Agreement is being purchased for investment only and Purchaser  understands that
the stock is an unregistered security under federal and state law.

     9. Continuing Nature of Representations and Warranties It is understood and
agreed that the representations,  warranties, covenants and agreements of Seller
and EDC  contained  herein shall survive the closing of the purchase and sale of
capital stock of Optichem and continue to be binding.

     10.  Indemnification by Seller.  Seller hereby agrees to indemnify and hold
Optichem  and  Purchaser  harmless  from  any and  all  liabilities,  costs  and
expenses, including reasonable attorney fees, paid by Purchaser or Optichem as a
result of the  operations of Optichem prior to the closing of this Agreement and
the transfer of stock, or as a result of a breach by Seller of any provisions of
this Agreement. In the event Purchaser or Optichem incur any liability,  cost or
expense pursuant to this Section, the Purchaser shall have the option of seeking
immediate  recovery  from  Seller,  deducting  any  liability,  cost or expenses
incurred  from the  quarterly  payments  due  under  this  Agreement;  provided,
however,  Seller shall have no obligation to indemnify Optichem or Purchaser for
any claim,  damage,  or loss  arising out of or  associated  with the defense or
validity of the licensed technology and License Agreement.

     11.  Inspection  of Records by Purchaser.  Prior to the closing  hereunder,
Seller will cause Optichem to permit EDC and its  representatives  to visit,  at
EDC's expense,  any of the property of Optichem,  to inspect its books,  records
and accounts  and to discuss its affairs and finances  with its officers at such
reasonable  times as EDC may desire and will  cause  Optichem  to furnish to EDC
such corporate  records of Optichem and other  documents as EDC may from time to
time  reasonably  request,  provided,  however,  that  any  furnishing  of  such
information to EDC and any  investigation by EDC shall not affect EDC's right to
rely on the representations and warranties made by Seller hereinabove.

     12.  Obligation to Close.  The  obligation to  consummate  the  transaction
contemplated herein is subject to the fulfillment,  on or before the date of the
closing, of the following conditions:

     (a) all representations and warranties made by EDC herein shall be true and
correct at the time of the closing as if made again on and as of said date;

     (b) EDC shall have  performed and complied with all  covenants,  agreements
and  conditions  required by this Agreement to be performed and complied with by
it prior to or at the closing;

     (c) all  representations and warranties made by Seller herein shall be true
and correct at the time of the closing as if made again on and as of said date;

     (d) Seller shall have performed and complied with all covenants, agreements
and  conditions  required by this Agreement to be performed and complied with by
them prior to or at the closing.

     13. Continuation of Business. Until the closing, Seller agrees to cause the
business of Optichem to be conducted only in the ordinary  course and on a basis
consistent  with past practices.  Seller will not cause Optichem,  without EDC's
written consent, to (i) declare or pay any dividend on any outstanding shares of
its  capital  stock  (other  than  regular  cash  dividends  declared on a basis
consistent with past  practices) or acquire any such shares,  Or declare or make
any other  payments  or  distributions  of assets  to its  shareholders,  except
payment of compensation for services rendered  consistent with past practices or
(ii) issue  shares of its  capital  stock or options to  purchase  any  thereof,
purchase or redeem any  outstanding  shares of its capital  stock,  or amend its
Articles of Incorporation in any way.

     14. Closing. The closing shall take place at the offices of Optichem, or at
such other place or date as the parties may agree,  by April 15, 1992, or within
five (5) business days following receipt of all necessary  consents or approvals
and  completion  of  satisfactory  due diligence  reviews by  Purchaser.  At the
closing Seller shall deliver to EDC:

     (a) certificates  representing  all outstanding  shares of capital stock of
Optichem duly endorsed and in proper form for transfer to EDC;

     (b) the written resignation of all Directors of Optichem;

     (c) a certificate  confirming that all  representations and warranties made
by Seller  herein  remain true and correct at the time of the closing as if made
again on and as of said date, and confirming  further that Seller have performed
and complied with all  covenants,  agreements  and  conditions  required by this
Agreement to be performed  and complied with by them prior to or at the closing;
and

     (d) all share certificates and corporate records of Optichem,  specifically
including but not limited to the original License Agreement between Optichem and
Perfect View, Inc. dated December 16, 1986.

     EDC shall deliver to Seller at the closing:

     (a) a certified copy of the  resolutions  adopted by the Board of Directors
of EDC authorizing this Agreement and the consummation of the transaction herein
contemplated; and

     (b) a  certificate  from an executive  officer of EDC  confirming  that all
representations and warranties made by EDC herein remain true and correct at the
time of the  closing  as if made again on and as of said  date,  and  confirming
further that EDC has performed and complied with all  covenants,  agreements and
conditions  required by this  Agreement to be performed  and complied with by it
prior to or at the closing.

     In the  event  that  the  closing  does not take  place  in  person  at one
location,  Seller  agrees to execute all  documents  and  provide  the  original
agreements, exhibits, certificates, corporate records, and stock certificates to
Purchaser, to be held in escrow by Robinson, McFadden & Moore, P.C. at 1901 Main
Street, Columbia, South Carolina, until Purchaser has executed all documents and
provided a fully  executed  original  agreement  and all exhibits and  necessary
certificates to Seller.

     15. No Brokers. EDC and the Seller represent and warrant to each other that
no broker has been employed in  connection  with the sale  contemplated  by this
Agreement  and the Seller  agrees to indemnify  the  Purchaser and the Purchaser
agrees to  indemnify  the Seller  against  all loss,  cost,  damage or  expense,
including  reasonable  attorney's  fees,  arising  out  of or  resulting  from a
judicially valid claim based upon employment by the other of a broker.

     16.  Notices.  All notices,  requests,  demands,  and other  communications
hereunder  shall be in  writing,  and shall be deemed to have been duly given if
delivered or mailed first class postage prepaid, if to

         Seller:
                           J. Buck Dowdy
                           3301 Bramer Drive
                           Raleigh, North Carolina 27604

         With a Copy to:
                           Adam H. Broome, Esquire Petree, Stockton
                           Post office Box 300004
                           Raleigh, North Carolina 27622

         Purchaser:
                           Robert J. Nagy, Secretary
                           Envirometrics Development Co., Inc
                            9229 University Blvd.
                           Charleston, South Carolina, 29418

         With a Copy to:
R.       William Metzger, Jr., Esquire Robinson, McFadden & Moore, P.C.
                           Post Office Box 944
                           Columbia, South Carolina, 29202

     17.  Entire   Agreement.   This  Agreement  is  the   consummation  of  all
negotiations   between  Seller  and  Purchaser  or  any  related   entities  and
constitutes the entire contract between EDC and the Seller and no warranties and
representations have been made by either which are not contained herein.

     18.  Modification  of  Agreement.  This  Agreement  may not be  changed  or
modified  except by a similar  instrument  in  writing  executed  by EDC and the
Seller.

     19.   Counterparts  to  Agreement.   This  Agreement  may  be  executed  in
counterparts,  each of which when so executed shall be deemed to be an original,
and such counterparts shall together constitute but one and the same instrument.

     20. Binding  Effect.  This  Agreement  shall be binding on and inure to the
benefit  of  Seller,  their  heirs-at-law,  legatees,  distributees,  executors,
administrators  and other  legal  representatives,  and shall be  binding on and
inure to the benefit of EDC, its successors and assigns.

     IN WITNESS WHEREOF,  the parties hereto have herein  respectively  executed
this Agreement.

                       ENVIROMETRICS DEVELOPMENT CO., INC

                              By: R. William Metzer
                                 Its: President

ATTEST

_____________________________________
Robert J. Nagy, Secretary
(Affix Corporate Seal)               J. BUCK DOWDY

                            ________________________

                                    EXHIBIT A

                                       TO

                              SHARE PURCHASE AGREE
                       ENTERED INTO AS OF OCTOBER 17, 1991

                            DISCLOSURE OF LIABILITIES

     To the actual knowledge of Seller, the following items represent all of the
outstanding   obligations  and  liabilities  of  Optichem   Technologies,   Inc.
("Optichem") as of April 15, 1992:

     1. All obligations and duties under the License  Agreement,  dated December
16, 1986, by and between Optichem and Perfect View, Inc.

     2.  All  claims  and  liabilities,   actual  and  contingent,  asserted  by
Sensidyne,  Inc. as described in that certain  letter dated April 3, 1992,  from
Sensidyne, Inc. to Optichem.

     3. All liens,  encumbrances and liabilities associated with the outstanding
obligations  of  Optichem  under  that  certain  Promissory  Note to the Town of
Morrisville,  North  Carolina  with a balance  in the  amount  of  Thirty  Seven
Thousand Seven Hundred Forty-six and 26/100 Dollars  ($37,746.26) as of June 30,
1992.

                                  Exhibit B to
                      Purchase Agreement entered into as of
                                October 17, 1991

             ELECTION TO CLOSE BOOKS UPON S CORPORATION TERMINATION

     Optichem  Technologies,  Inc. (the "Corporation"),  with the consent of all
the  shareholders  of the  Corporation  during  the  short  S year  and  all the
shareholders  of the  Corporation  on the first day of the short C year,  elects
under Section 1362 (e) (3) of the Internal Revenue Code of 1986, as amended (the
"Code"),  not to have the pro rata allocation of S corporation  items under Code
Section 1362 (e) (2) apply to the S termination  year ending #I 19 9 2. The date
of termination of the  Corporation's S termination was the purchase of its stock
by a C corporation.

Date:                                            Optichem Technologies,  Inc.

                                            By:
                                            Its:

                                                  CONSENT OF SHAREHOLDERS

     The  undersigned,  being  all the  shareholders  owning  any  stock  of the
Corporation during the short S year and all the shareholders owning stock on the
first day of the short C year,  hereby  consent  to the  above  election  by the
Corporation  under Code  Section  1362 (e) (3) not to apply the rules under Code
Section  1362(e)(2)  to  the  S  termination  year  ending  1992.  The  date  of
termination of the Corporation's S corporation status was , 1992

                                     Date:
                                  J. Buck Dowdy
                          Identification No. 24062-4052

                                     Date:
                      Envirometrics Development, Co., Inc.
                                       By:
                                      Its:

                                    EXHIBIT C
           CORPORATE RESOLUTION OF ENVIROMETRICS DEVELOPMENT CO., INC.
                              DATED APRIL 13, 1992

     BE IT  RESOLVED  that  pursuant to a meeting of the Board of  Directors  of
Envirometrics  Development  Co.,  Inc.  (the  "Corporation")  that the  Board of
Directors unanimously  authorized the Corporation to enter into a Share Purchase
Agreement to purchase all outstanding shares of stock in Optichem  Technologies,
Inc., a North Carolina corporation,  pursuant to the terms and conditions of the
Share Purchase Agreement between the parties dated October 17, 1991.

     FURTHER BE IT RESOLVED that R. William Metzger, as President, and Robert J.
Nagy, a Secretary,  are authorized to execute the Share  Purchase  Agreement and
any and all other documents related thereto.

     This  Resolution  adopted  this  13th  day of  April,  1992.

                                  ENVIROMETRICS
                  DEVELOPMENT CO, INC. By: R. William Metzger

                        Its: Chairman, Board of Directors

ATTEST:

Robert J. Nagy, Secretary
(Affix Corporate Seal)

                                CLOSING AGREEMENT

     THIS CLOSING AGREEMENT is made, entered into and effective this 16th day of
April, 1992, by and between OPTICHEM  TECHNOLOGIES,  INC. ("OPTICHEM") , a North
Carolina corporation, ENVIROMETRICS DEVELOPMENT CO., INC. ("PURCHASER"), a South
Carolina Corporation; and J. BUCK DOWDY ("SELLER").

     NOW,  THEREFORE,  in consideration  of the mutual promises,  agreements and
covenants made hereunder,  and other good and valuable consideration received by
each party hereto,  the  sufficiency and receipt of which is acknowledged by all
such parties, the parties hereto agree as follows:

     1. DISCLOSURE OF ALL MATERIAL,  INFORMATION.  PURCHASER  acknowledges that,
all  information  (financial  or  otherwise)  necessary for PURCHASER to reach a
decision to purchase the stock of SELLER  under the terms and on the  conditions
of that certain Share Purchase Agreement,  dated October 17, 1991 by and between
PURCHASER and SELLER, has been provided to and examined by PURCHASER.  PURCHASER
further  understands  that third  parties  (other than SELLER) have disputed and
challenged  the  enforceability  and  validity of the License  Agreement,  dated
December 16,  1986,  between  OPTICHEM  and Perfect  View,  Inc.  (the  'License
Agreement")  and the right of  Licensor  to grant the  license.  Such  claims if
valid,   will  prevent  OPTICHEM  or  any  other  party,   from   manufacturing,
distributing and selling any product utilizing the licensed  technology pursuant
to the License Agreement.  PURCHASER specifically acknowledges that, pursuant to
a letter dated April 3, 1992, Sensidyne, Inc. has claimed that:

     (i) it  holds  all  rights  and  interests  to the  patents  issued  on the
application referenced in the License Agreement; and

     (ii) the License  Agreement  is,  among other  reasons,  unenforceable  and
invalid due to the Licensor,  Perfect View, Inc., having no rights and interests
in the underlying patents, that the License Agreement has expired by its express
terms and that the License is  nontransferable,  directly or indirectly,  to any
party.

     Sensidyne has  threatened to pursue all available  remedies  against SELLER
and any other party,  including PURCHASER,  and in likely to commence litigation
it necessary to defend its position.

     2.  IDEMNIFICATION  OF SELLER BY PURCHASER.  PURCHASER  hereby assumes full
responsibility for the discharge and satisfaction of all claims,  costs, losses,
damages,  penalties,  fines and expenses that PURCHASER or OPTICHEM may incur in
connection  with the above  matters.  PURCHASER  further  agrees to defend (with
counsel reasonably  satisfactory to SELLER) , hold harmless and indemnify SELLER
from any and all claims, costs, losses, damages,  penalties, fines, and expenses
including reasonable  attorneys,  fees of SELLER,  resulting Or arising from (1)
any of the matters in  paragraph I above;  (2) the  defense  enforceability,  or
validity of the licensed technology or License Agreement; and (3) the operations
of Optichem on and after the closing of this transaction which were not a result
of the breach of any provision of this Agreement or the Share Purchase Agreement
executed  concurrently  herewith and  incorporated  herein by reference.  SELLER
acknowledges that PURCHASER shall have control and authority over any litigation
in which  PURCHASER  defends  SELLER  and the costs  associated  therewith,  and
PURCHASER  will use its best  efforts  to obtain  counsel  for  SELLER  which is
reasonably  satisfactory to SELLER, however, in the event that a mutually agreed
upon counsel  cannot be chosen,  SELLER has the option of  obtaining  individual
counsel  but will be  responsible  for all fees and costs  associated  with said
independent counsel.

     3. INDEMNIFICATION OF PURCHASER BY SELLER. The outstanding debt of OPTICHEM
to the Town of  Morrisville,  North  Carolina  in the  amount  of  Thirty  Seven
Thousand Seven Hundred Forty-Six and 26/100 Dollars ($37,746.26),  which matures
on June. 30, 1992,  shall be the  responsibility  of SELLER.  In addition to any
obligation of SELLER to indemnify PURCHASER under the Share Purchaser Agreement,
SELLER hereby agrees to indemnify and hold harmless  PURCHASER and OPTICHEM from
and against such  liability in accordance  with Section 9 of the Share  Purchase
Agreement.

                  PURCHASER: ENVIROMETRICS DEVELOPMENT CO. INC.

                                       BY:

ATTEST:

(Asst.) Secretary

         [CORPORATE SEAL]

                                    SELLER:
                                  J. BUCK DOWDY

                             SELLER'S CERTIFICATE OF
                  AFFIRMATION OF REPRESENTATIONS AND WARRANTIES

     Pursuant  to  Share  Purchase   Agreement   ("AGREEMENT")  by  and  between
ENVIROMETRICS DEVELOPMENT Co., INC. ("PURCHASER") ; OPTICHEM TECHNOLOGIES,  INC.
("SELLER) ; SELLER hereby represents, warrants and certifies that:

     All of the representations,  warranties and covenants made by SELLER in the
AGREEMENT are true and correct on April 16, 1992 (the  "CLOSING  DATE,,) and all
of the terms and  conditions  of the AGREEMENT to be complied with and performed
by SELLER on or prior to the  CLOSING  DATE have been timely  complied  with and
performed.

SELLER:
                              J. Buck Dowdy, Seller

                           PURCHASER'S CERTIFICATE OF
                  AFFIRMATION OF REPRESENTATIONS AND WARRANTIES

     Pursuant  to  Share  Purchase   Agreement   ("AGREEMENT")  by  and  between
ENVIROMETRICS  DEVELOPMENT CO., INC.  ("PURCHASER")  and OPTICHEM  TECHNOLOGIES,
INC. ("SELLER") ; PURCHASER hereby represents, warrants and certifies that:

     All of the  representations,  warranties and covenants made by PURCHASER in
the AGREEMENT are true and correct on April 16, 1992 ("CLOSING DATE") and all of
the terms and  conditions  of the AGREEMENT to be complied with and performed by
PURCHASER  on or prior to the CLOSING  DATE have been timely  complied  with and
performed.

PURCHASER:                          ENVIROMETRICS DEVELOPMENT CO., INC

                                      By:
                                  Its President

                                 April 16, 1992

Optichem Technologies, Inc.
9229 University Blvd
Charleston, South Carolina 29418

Gentlemen:

     The undersigned as sole director of Optichem Technologies, Inc. does hereby
tender his resignation as Director of the Corporation.  The undersigned  further
represents that all existing officers have tendered their  resignations and that
said resignations have been approved and accepted.

                                                       J. Buck Dowdy
                                                       Sole Director

OPTICHEM TECHNOLOGIES, INC.

HEREBY ACCEPTED

By:AGREEMENT

     THIS AGREEMENT is entered into this day of 1 1992, by and between  Computer
Control  Corporation,  a New  Jersey  corporation  having  offices  at 230  West
Parkway, Pompton Plains, New Jersey 07444 ("Computer Control") and Envirometrics
Development  Company,  Inc., a South Carolina corporation having offices at 9229
University Boulevard,  North Charleston,  South Carolina 29418 ("Envirometrics")
WITNESSETH

     WHEREAS,  Computer  Control  is  in  the  business  of  developing  various
electronic  devices with  integrated  computer  capabilities  for the industrial
hygiene/environmental market; and

     WHEREAS,   Envirometrics  desires  to  have  Computer  Control  develop  an
electronic  reader for utilization with a new line of passive air monitors based
upon  photometry  devices  which change color or other  optical  characteristics
after exposure to airborne chemicals.

     NOW,  THEREFORE,  in  consideration of the above premises and the covenants
hereinafter set forth, the parties hereto do hereby agree as follows:

     1.  Computer  Control  hereby  agrees to use its best efforts to develop an
electronic  reader (the "Reader") for utilization with  Quantitative  Photometry
Monitors.  For purposes of this Agreement,  a "Quantitative  Photometry Monitor"
shall mean a passive air monitor  based upon  photometry  devices  which  change
color or other optical  characteristics after exposure to airborne chemicals and
which can be utilized  with an electronic  reader.  The Reader shall satisfy the
specifications set forth on Schedule A hereto,  subject to such modifications to
such specifications as the parties shall mutually agree.

     2.  Envirometrics  hereby agrees to make the following payments to Computer
Control:

     a. Upon execution of this  Agreement,  Envirometrics  shall pay to Computer
Control the sum of $10,000.00.

     b. Upon  completion  of a  prototype  Reader by June 1,  1992  which  shall
satisfy  the  specifications  set forth on  Schedule A hereto  (subject  to such
modifications  to such  specifications  as the parties shall  mutually  agree) ,
Envirometrics shall pay to Computer Control an additional $20,000.00.  If such a
prototype  is  not  completed  by  June  1,  1992,  (i)  this  Agreement   shall
automatically terminate, (ii) Computer Control shall return to Envirometrics the
$10,000.00  payment made by  Envirometrics  pursuant to  subparagraph  2(a), and
(iii) both parties shall be relieved of all further obligations hereunder.

     C.  Envirometrics  hereby agrees to pay to Computer Control a royalty equal
to 3% of gross revenues collected from sales of Quantitative Photometry Monitors
by Envirometrics  during the five year period  commencing upon the first sale by
Envirometrics  of a Reader  (the  "Monitor  Royalty  Period").  It is  expressly
understood  that  royalties  shall be  payable  on all  revenues  in  respect of
Quantitative  Photometry  Monitors  which are sold  during the  Monitor  Royalty
Period, including revenues from such sales which are collected after the Monitor
Royalty Period.  The minimum royalty which  Envirometrics  shall pay to Computer
Control  pursuant to this  clause (c) for the first year of the Monitor  Royalty
Period shall be $25,000.00 and the minimum royalty which Envirometrics shall pay
to  Computer  Control  pursuant  to this  clause (c) for the second  year of the
Monitor Royalty Period shall be $30,000.00.

     d. Envirometrics  shall also pay to Computer Control a royalty equal to 10%
of gross  revenues  collected  from  sales,  rentals  and  leases of  Readers by
Envirometrics  during  the five year  period  commencing  upon the first sale by
Envirometrics  of a Reader  developed by Computer  Control (the "Reader  Royalty
Period";  provided,  however,  that if Computer Control shall obtain a patent on
the Reader,  the Reader  Royalty  Period shall  continue until the expiration of
such patent.  It is expressly  understood that royalties shall be payable on all
revenues  in  respect  of Readers  which are sold,  rented or leased  during the
Reader Royalty Period,  including  revenues from such sales,  rentals and leases
which are  collected  after the  Monitor  Royalty  Period.  Notwithstanding  the
foregoing,  no royalty shall be payable by  Envirometrics  in respect of Readers
Purchased by Envirometrics from Computer Control.

     e.  Envirometrics  shall  reimburse  Computer  Control  for all legal fees,
filing  fees and other  out-of-pocket  costs  incurred  by  Computer  Control in
connection with obtaining patents on the Reader or any components thereof or any
technology  incorporated  therein ("Patent Costs"), up to $5,000.00;  all Patent
Costs  incurred by  Computer  Control in excess of  $5,000.00  shall be borne by
Computer  Control.  Envirometrics  shall reimburse  Computer  Control for Patent
Costs in accordance  with the preceding  sentence within ten (10) days following
submission of an invoice by Computer Control.

     3. The  technology  utilized by Computer  Control to develop the Reader and
the technology  embodied in the Reader,  to the extent not already in the public
domain,  shall be and remain the  property  of  Computer  Control.  All  patents
awarded shall be owned by Computer Control.

     4. Computer Control hereby grants to  Envirometrics an exclusive  worldwide
license to  manufacture  and sell Readers for use with  Quantitative  Photometry
Monitors;  provided,  however,  that Computer  Control reserves the nonexclusive
right to  manufacture  and sell Readers to  Envirometrics.  The license  granted
hereunder shall not be assignable.  Envirometrics  may not sublicense its rights
under the license  granted  hereunder.  The license  granted  hereunder shall be
perpetual,  subject,  however,  to termination by either party in the event of a
breach of this  Agreement  by the other party which  remains  uncured for thirty
(30) days  following  notice of such  breach by the  non-breaching  party to the
breaching party. It is expressly  understood that Computer Control reserves unto
itself the  exclusive  right to utilize  the  technology  utilized  by  Computer
Control to develop the Reader and the technology  embodied in the Reader for any
purpose other than the manufacture and sale of Readers for use with Quantitative
Photometry  Monitors.  In order to enable  Envirometrics to manufacture Readers,
Computer Control shall disclose to Envirometrics all technical  know-how,  trade
secrets and  proprietary  information  of Computer  Control which is required to
manufacture  Readers.  All such trade secrets and proprietary  information shall
remain the sole and exclusive property of Computer Control.

     5. The royalties  payable  pursuant to clauses l(c) and l(d) above shall be
computed and paid quarterly.  Within fifteen (15) days following the end of each
calendar  quarter  during  the  respective   royalty  periods  for  Quantitative
Photometry  Monitors and Readers,  and  Envirometrics  shall furnish to Computer
Control a  statement  of the gross  revenues  during  such  calendar  quarter of
Envirometrics  from the sale of  Quantitative  Photometry  Monitors and from the
sale,  leasing and rental of Readers  and of the  royalty due for such  calendar
quarter.  Within  fifteen (15) days  following the end of each calendar  quarter
during the year following the termination of the respective  royalty periods for
Quantitative  Photometry  Monitors and Readers,  Envirometrics  shall furnish to
Computer  Control a statement of the gross revenues during such calendar quarter
of Envirometrics  from the sale of Quantitative  Photometry  Monitors which were
sold during the Monitor Royalty Period and from the sale,  leasing and rental of
Readers  during  the  Reader  Royalty  Period  and of the  royalty  due for such
calendar  quarter.  Each such  statement  shall be accompanied by payment of the
royalty due.  Envirometrics  agrees to keep accurate records pertaining to sales
of Quantitative  Photometry  Monitors and sales,  leases and rentals of Readers.
Computer Control shall have the right to inspect and make copies of such records
upon reasonable notice to Envirometrics. In the event of a dispute regarding the
computation of royalties payable  hereunder,  Computer Control and Envirometrics
shall attempt to resolve the dispute among  themselves and adjust the applicable
statement and royalty payment.  In the event Computer Control and  Envirometrics
are unable to resolve the dispute  within thirty (30) days  following  notice by
Computer Control to Envirometrics of a dispute, then they shall attempt to agree
upon a nationally  recognized  accounting firm to act as "Umpire" hereunder.  In
the event  Computer  Control  and  Envirometrics  are unable to select an Umpire
within five days following the end of said thirty (30) day period,  then each of
the parties will select a nationally  recognized accounting firm within ten (10)
days  following  the end of said thirty (30) day  period,  and those  accounting
firms shall agree upon a third nationally recognized accounting firm to serve as
Umpire within twenty (20) days following the end of said thirty (30) day period.
The  nationally-recognized  accounting  firm which is  selected to act as Umpire
hereunder  shall  review  the  books  and  records  of  Envirometrics  and shall
determine the amount of royalties  which should have been paid in respect of the
periods in question.  The determination of the Umpire shall be final and binding
on the parties. Each party shall bear whatever fees and expenses are incurred by
the accounting firm selected by it. In the event that the Umpire determines that
there has been an underpayment of royalties, the Umpire's fees shall be borne by
Envirometrics;  in the event that the Umpire  determines that there has not been
an  underpayment  of  royalties,  the  Umpire's  fees shall be borne by Computer
Control.

     6.  In  the  event  the  Reader  is  ever  held  by a  court  of  competent
jurisdiction to infringe any patent or patents owned by others, Computer Control
shall have the right,  at its own  expense,  to redesign the reader to avoid the
infringement or obtain a license to enable Envirometrics to continue to sell the
Reader.  If  within  ninety  (90)  days  following  a  final   determination  of
infringement,  Computer  Control fails to redesign the Reader so as to avoid the
infringement or to obtain a license,  then Envirometrics may forthwith terminate
all its  obligations  outlined  under clauses l(c) and l(d) above.  In the event
Envirometrics  is named  as a  defendant  in a suit  alleging  that  the  Reader
infringes  any patent or patents  owned by others and  Computer  Control is also
named as a  defendant  in the suit,  then  Computer  Control  shall  control the
defense and settlement of the suit and  Envirometrics and Computer Control shall
each  bear  50% of the cost of  defending  and  settling  such  suit;  provided,
however,  that the  selection  of a law  firm to  defend  any such  suit and any
settlement  thereof  shall be subject to the  approval of  Envirometrics,  which
approval  shall  not  be  unreasonably   withheld  or  delayed.   In  the  event
Envirometrics  is named  as a  defendant  in a suit  alleging  that  the  Reader
infringes any patent or patents owned by others and Computer Control is not also
named as a defendant in the suit, then  Envirometrics  shall control the defense
and settlement of the suit and Computer  Control shall  reimburse  Envirometrics
for 50% of the cost of  defending  and  settling  such suit.  Envirometrics  and
Computer Control shall provide reasonable  cooperation to one another, and shall
keep one another apprised of developments in, any such suit

     7. In the event of  infringement  of the herein  proposed  licensed  patent
rights by others,  Computer  Control  shall have the right to, but shall have no
duty to,  enforce  said patent  rights.  If Computer  Control  does not agree to
enforce said Patent rights within sixty (60) days following a written request by
Envirometrics that it do so, then Computer Control shall assign to Envirometrics
the right to enforce said patent  rights  against the party or parties  named in
the request, in which case the expenses of any such litigation shall be borne by
Envirometrics and Envirometrics  shall be entitled to any recovery on account of
infringement.  Computer Control shall provide reasonable cooperation in any such
enforcement   action  upon  the   request  of   Envirometrics,   provided   that
Envirometrics shall reimburse Computer Control for its reasonable  out-of-pocket
expenses incurred by Computer Control in providing such cooperation.

     8. Computer  Control  represents and warrants that (i) it has all requisite
corporate  power and  authority to enter into this  Agreement and to perform its
obligations  hereunder;  (ii) this  Agreement  constitutes  a valid and  binding
obligation of Computer  Control,  enforceable in accordance with its terms;  and
(iii)  neither the  execution  nor  performance  of this  Agreement  by Computer
Control has or will  violate any  provisions  of Computer  Controls  Articles of
Incorporation  or Bylaws or of any  material  agreement or  instrument  to which
Computer Control is a party or by which Computer Control is bound.

     9.  Envirometrics  represents  and warrants  that (i) it has all  requisite
corporate  power and  authority to enter into this  Agreement and to perform its
obligations  hereunder;  (ii) this  Agreement  constitutes  a valid and  binding
obligation of  Envirometrics,  enforceable in accordance  with its terms;  (iii)
neither the execution nor performance of this Agreement by Envirometrics  has or
will violate any  provisions  of  Envirometrics'  Articles of  Incorporation  or
Bylaws or of any material  agreement or instrument to which  Envirometrics  is a
party or by which  Envirometrics  is bound; and (iv) the manufacture and sale of
Quantitative  Photometry  Monitors by Envirometrics  and the use of Quantitative
Photometry  Monitors in conjunction  with Readers will not violate any patent or
other rights of any third parties.  Envirometrics  covenants that it shall, upon
delivery of the prototype Reader due June 1, 1992, deliver to Computer Control a
true and complete copy of a valid license to  Envirometrics  for the manufacture
and sale of Quantitative  Photometry Monitors worldwide for a period of not less
than six (6) years from the date hereof,  which  license  shall be in full force
and  effect  on the date  hereof.  Envirometrics  hereby  covenants  to take all
actions necessary to maintain the license referred to in the preceding  sentence
in good standing until the  termination of the Monitor  Royalty  Period.  In the
event  Computer  Control is named as a  defendant  in a suit  alleging  that the
manufacture,  use or sale of Quantitative  Photometry Monitors,  or their use in
conjunction  with  Readers,  infringes  any patent or  patents  owned by others,
Envirometrics shall bear the cost of defending and settling such suit.

     10. (a) Computer  Control  hereby  covenants to indemnify and hold harmless
Envirometrics  from  and  against  any and  all  damages,  losses,  obligations,
liabilities,  claims,  actions  or causes of action  sustained  or  suffered  by
Envirometrics  and  arising  from a  breach  of any  agreement,  representation,
warranty or covenant of Computer  Control  contained in or made pursuant to this
Agreement,  including  all  reasonable  costs and expenses  (including,  without
limitation,  reasonable attorneys' fees) incurred by Envirometrics in connection
therewith.

     (b) Envirometrics  hereby covenants to indemnify and hold harmless Computer
Control from and against any and all damages, losses, obligations,  liabilities,
claims,  actions or causes of action  sustained or suffered by Computer  Control
and arising from a breach of any agreement, representation, warranty or covenant
of Envirometrics contained in or made pursuant to this Agreement,  including all
reasonable  costs  and  expenses  (including,  without  limitation,   reasonable
attorneys' fees) incurred by Computer Control in connection therewith.

     In the course of negotiating  and performing  this  Agreement,  the parties
have and will continue to provide to one another  proprietary  and  confidential
product,  financial and technical information,  including but not limited to (a)
the  specifications  contained  on  Exhibit A hereto  which  were  developed  by
Envirometrics,   (b)  information  regarding  Quantitative  Photometry  Monitors
manufactured  or being  developed by  Envirometrics,  (c) sales  information  of
Envirometrics  and  (d)  technical  know-how,   trade  secrets  and  proprietary
information now owned by Computer  Control or which may be developed by Computer
Control in connection with this project,  including  technical  know-how,  trade
secrets and proprietary  information  required to manufacture Readers (hereafter
referred to as "Confidential  Information") . Confidential  Information includes
not only written information but also information transferred orally,  visually,
electronically  or by any  other  means.  Each  of  the  parties  hereto  hereby
covenants that (i) it will use the other party's Confidential Information solely
for the  purposes  permitted  by this  Agreement  and  (ii) it  shall  keep  all
Confidential  Information of the other party secret and  confidential  and shall
not disclose it to anyone  except to a limited  group of its own  employees  and
consultants who are actually engaged in the design,  development and manufacture
of Readers. Each person to whom such Confidential  Information is disclosed must
be advised of its  confidential  nature and of the terms of this  agreement  and
prior to receiving any Confidential Information thereof (unless already bound by
obligations  of  confidentiality)  must agree to abide by such  terms.  The term
"Confidential  Information" does not include information which (i) is already in
the  possession of the receiving  party,  provided that such  information is not
known by the receiving party to be subject to another confidentiality  agreement
with or other  obligation of secrecy to the  disclosing  party,  or (ii) becomes
generally  available to the public other than as a result of a disclosure by the
receiving party or its directors,  officers,  employees,  agents or advisors, or
(iii) becomes available to the receiving party on a non-confidential  basis from
a source other than the  disclosing  party or its  advisors,  provided that such
source  is not  known by the  receiving  party to be bound by a  confidentiality
agreement with or other obligation of secrecy to the disclosing party or another
party,  or (iv) has been  independently  acquired or developed by the  receiving
party without  violating any of its  obligations to the  disclosing  party under
this  Agreement.  In the  event  that a  receiving  party  or  anyone  to whom a
receiving party transmits  Confidential  Information  pursuant to this Agreement
becomes legally compelled to disclose any of the Confidential Information,  such
receiving party will provide the disclosing party with prompt notice so that the
disclosing party may seek a protective order or appropriate  remedy and/or waive
compliance  with the  provisions  of this  Agreement;  in the  event  that  such
protective  order or other remedy is not obtained or that the  disclosing  party
waives  compliance  with the provisions of this  Agreement,  the receiving party
will  furnish  only that  portion of the  Confidential  Information  which it is
advised by counsel is legally required.

     12. The following shall constitute Events of Default hereunder: (i) Failure
by  either  party  hereto to make any  payment  due  hereunder  on the date such
payment  is due,  provided  such  failure  is not  cured  within  ten (10)  days
following the giving of written notice of such breach to the breaching  party by
the nonbreaching  party;  (ii) the material breach by either party hereto of any
covenant,  representation or warranty contained herein,  other than covenants to
pay money,  provided such breach is not cured within thirty (30) days  following
the  giving of  written  notice of such  breach  to the  breaching  party by the
nonbreaching  party;  or (iii) if either party hereto  should ever be adjudged a
bankrupt.  If an Event of Default shall have  occurred and shall be  continuing,
the  nondefaulting  party  may,  by  written  notice  to the  defaulting  party,
terminate  this  Agreement,  whereupon  both  parties  shall be  relieved of all
further obligations  hereunder and the license granted in Section 4 hereof shall
immediately  terminate.  The remedy  provided for above shall be in addition to,
and not in lieu of, any and all other rights and remedies which either party may
have at law or in equity in the event of a breach of this Agreement by the other
party.

     13. This Agreement  shall be binding upon,  inure to the benefit of, and be
enforceable by, the parties hereto and their respective successors and permitted
assigns.  If Computer  Control  sells,  assigns or transfers  any patent  rights
obtained or created as a result of this  Agreement,  the terms and conditions of
this Agreement shall be binding on the purchaser, assignee or transferee of such
rights,  and  Envirometrics  shall  continue to pay the royalties due under this
Agreement to Computer Control absent written notice from Computer Control to the
contrary. Nothing expressed or implied in this Agreement is intended or shall be
construed to confer upon or give to any person other than the parties hereto any
rights  or  remedies  under or by reason of this  Agreement  or any  transaction
contemplated hereby.

     14. This Agreement  contains the entire  understanding  of the parties with
respect to its subject matter.  This Agreement  supersedes all prior  agreements
and  understandings  between the  parties  with  respect to its subject  matter.
Without  limiting the  generality of the foregoing,  there are no  restrictions,
promises,  representations,  warranties,  covenants or understandings other than
those expressly set forth or referred to herein.

     15. This  Agreement  may be amended,  modified  or  supplemented  only by a
written instrument duly executed by the parties hereto.

     16. Neither this Agreement nor any of the rights,  interests or obligations
hereunder  shall be assigned or  sub-licensed by either party hereto without the
prior  written  consent of the other party  hereto.  In the event of a permitted
assignment  by either party of this  Agreement,  the  assignor  shall cause such
assignee to assume all of the assignor's obligations hereunder, which assumption
shall be by a written  instrument  addressed to both parties  hereto in form and
substance  reasonably  satisfactory to the non-assigning  party and its counsel.
Provided,  the sale of the stock of either  party  hereto  shall not require the
consent of the other party. In the event that Envirometrics  intends to sell all
or  substantially  all of its assets,  it shall notify Computer Control at least
twenty  (20) days  prior to such sale and,  if  requested  to do so by  Computer
Control within ten (10) days of the giving of such notice,  Envirometrics  shall
assign its rights hereunder to the purchaser of such assets and shall cause such
purchaser  to  assume  all  of  Envirometrics'   obligations  hereunder,   which
assumption  shall be by a written  instrument  addressed  to  Envirometrics  and
Computer  Control in form and  substance  reasonably  satisfactory  to  Computer
Control and its counsel.

     17.  All  notices,  claims,  certificates,   requests,  demands  and  other
communications  hereunder  shall be in writing  and shall be deemed to have been
duly  given  if  delivered  personally,  sent  by  facsimile  transmission  (and
confirmed by mail) or mailed (by  registered or certified  mail,  return receipt
requested and postage prepaid) to the parties as follows:

                    If to Computer Control:

                           Computer Control Corporation
                           230 West Parkway
                           Pompton Plains, New Jersey 07444
                           Attention: Mr. Harvey Padden, President
                            Fax No.: 201-839-7445
                  with copy to:

                           Stuart M. Geschwind, Esq.
                           Williams, Caliri, Miller & Otley
                           1428 Route 23
                           Wayne, New Jersey 07470
                           Fax No.: 210-694-0302

                            If to Seller:
                           Environmetrics Development Company, Inc.
                           9229 University Boulevard
                           North Charleston, South Carolina 29418
                           Attention: Mr. R. William Metzger, CEO
                                                     Fax No.:
                                                   with copy to:

                           Attention:

                                                     Fax No.:

     or to such other address or facsimile number as the party to whom notice is
to be given may have  furnished  to the other  parties in writing in  accordance
herewith.  Any such communication shall be deemed to have been given on the date
it is received by the  addressee  (as  evidenced,  in the case of  registered or
certified  mail,  by the date noted on the return  receipt) . Provided  that any
communication  sent by facsimile  transmission  and confirmed by mail,  shall be
deemed to have been given at the time of transmission.

     18. This  Agreement may be executed in any number of  counterparts,  and by
the different parties on separate counterparts, and each such counterpart hereof
shall be deemed to be an original instrument, but all such counterparts together
shall constitute but one agreement. 9

     19. This Agreement and the legal relations between the parties hereto shall
be governed by and  construed  in  accordance  with the laws of the State of New
Jersey, without giving effect to the choice of law principles thereof.

     20. Any  reference  expressed in any gender shall be deemed to include each
of the other genders, and the singular shall be deemed to include the plural and
vice versa, unless the context otherwise requires.  The term "person" as used in
this  Agreement,  unless the  context  otherwise  requires,  shall  include  any
individual and any  corporation,  partnership,  association,  or other entity or
group.  This  Agreement has been jointly  prepared by the parties hereto and the
terms  hereof shall not be construed in favor of or against any party on account
of its participation in such preparation.

     21. To the fullest  extent  permitted by applicable  law, any party to this
Agreement  may waive any  provision of this  Agreement;  provided,  that no such
waiver shall be of any force or effect unless the same is evidenced by a writing
executed by the party against which  enforcement  of such waiver is sought.  The
waiver by any party  hereto of a failure  of any  condition  or of any breach of
this  Agreement  shall not operate or be  construed  as a waiver of, or estoppel
with respect to, any subsequent or other failure or breach.

     22.  Each  of the  parties  hereto  agrees  to  execute  and  deliver  such
instruments and take such other actions as any other party hereto may reasonably
require in order to carry out the intent of this Agreement.

     23.  Upon  execution  of this  Agreement,  Envirometrics  shall  furnish to
Computer Control an attorneys  opinion,  addressed to Computer  Control,  in the
form of Schedule B hereto.

     IN WITNESS  WHEREOF,  the parties  hereto have executed  this  agreement in
duplicate.

                     ENVIROMETRICS DEVELOPMENT COMPANY, INC.

                                   Signed By:
                               R. William Metzger
                             Chief Executive Officer

                          COMPUTER CONTROL CORPORATION

                                   Signed By:
                                  Harvey Padden
                                    President

                                    GUARANTY

     Envirometrics,  Inc.,  as an  inducement  to Computer  Control  Corporation
("Computer  Control") to enter into the  preceding  Agreement  between  Computer
Control and Envirometrics Development Company, Inc. ("Envirometrics") , dated of
even date  herewith (the  "Agreement")  hereby  guarantees  the  performance  by
Envirometrics of Envirometrics' obligations under the Agreement.

                               ENVIROMETRICS, INC.

                                   Signed By:
                               R. William Metzger
                             Chief Executive Officer

                      EXHIBIT A - PRELIMINARY SPECIFICATION
                                 March 23, 1992
PHYSICAL:

         -     Portable
         -     Rechargeable battery, 8 hour operating life
         -     Charger can power unit on AC with discharged batteries
         -     Input: 16 position keypad
         -     Outputs: 16 character by 2 or 4 line LCD display
                              Parallel printer port (IBM compatible)
          -    single well design - Unit will memorize each badge's
               baseline (unexposed) value. 100 badge capacity.
          -    Program memory in user-changeable chip for updatesChip
               contains correction curves or tables for each badge type.

"INITIALIZE" OPERATING MODE:

-              Warning: All prior data will be cleared. Does user want to print?
-              Enter hazard type and badge ID (1 to 256)
-              Error warning if ID is already in use
-              Badge is inserted and unit stores baseline value

"READ"         OPERATING MODE:

               - Lowest  stored ID is  offered as a  default.  Subsequently  the
               number is  incremented  for each  badge.  Default  number  can be
               overwritten from keypad.

               - Relative  humidity  and  temperature  are entered for each read
               session.   Prior  values  are  offered  as  default  and  can  be
               overwritten.

               - Exposure time is entered for each badge. Prior value is offered
               as default and can be overwritten.

               - If badge is not already inserted, unit will prompt.

               - Computer will search by ID for previous reading and use it with
               present  reading  to  display:
                                                - Hazard
                                                - ID  number
                                                -  Interval concentration
                                                -  Cumulative concentration

               -  Computer  will ask  whether  to  store,,  warning  that  prior
               baseline will be destroyed. If printer is detected, unit will ask
               whether to print prior data before  overwriting  it.

               - Next  badge  ID is  offered  (and can be  overwritten)  "PRINT"
               OPERATING  MODE -  Continuous  print mode prints each  reading as
               taken

               - "Print" button allows printing on demand

               - "Batch" mode allows choice of ID range, all readings,  complete
               session or only previously unprinted readings

"CALIBRATE" OPERATING MODE

               - Prompts  to insert  white  card and  stores  reading  for later
               calculations

"OUT OF MEMORY WARNING"

               - If EEROM  is full,  user is asked  which  range of  samples  to
               delete (by ID,  previous  session or all).  User is prompted "Are
               you sure?" to make certain data is not lost accidentally.

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00000-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00000-of-00352.parquet"}]]