--------------------------

                              AMENDED AND RESTATED
                  UNLIMITED GUARANTY OF PAYMENT AND PERFORMANCE

                           --------------------------

     THIS AGREEMENT OF GUARANTY, dated as of this 1st day of July, 1999, between
Barringer Instruments Incorporated,  a Delaware corporation,  with offices at 30
Technology Drive,  Warren, New Jersey 07059, and Digivision,  Inc., a California
corporation,  with offices at 4775 Viewridge Avenue, San Diego, California 92123
(each being a "Guarantor",  and collectively,  the "Guarantors") and FLEET BANK,
N.A.  with  offices  at 1125  Route  22  West,  Bridgewater,  New  Jersey  08807
(hereinafter, together with any successor and assigns, "Lender").

                                   WITNESSETH:

     WHEREAS,   Barringer   Technologies  Inc.,  a  Delaware   corporation  (the
"Borrower")  is indebted to Bank  pursuant to a certain  Revolving  Credit Note,
dated March 13, 1998 (the "Note"), which evidences an obligation in the original
maximum principal balance of $5,000,000.00 (the "Loan"); and

     WHEREAS,  Barringer  Instruments  Incorporated,  executed and  delivered an
Unlimited  Guaranty of Payment and  Performance,  dated  March 13,  1998,  which
guaranteed the Borrower's obligations under the Note; and

     WHEREAS, Borrower has since acquired Digivision, Inc.; and

     WHEREAS, Borrower has requested that (i) Bank renew the Loan; and

     WHEREAS,  Lender is unwilling to renew the Loan without further security in
the form of an unconditional guaranty by the Guarantors; and

     WHEREAS, to induce Lender to grant the Loan to the Borrower, each Guarantor
herein executes the within instrument; and

     NOW,  THEREFORE,  in consideration of the premises contained herein and the
sum of ONE  ($1.00)  DOLLAR,  the receipt of which is hereby  acknowledged,  the
undersigned agree as follows:

     1.  Guaranty.   Each   Guarantor,   jointly,   severally,   absolutely  and
unconditionally  guarantees  to Lender  the due and prompt  payment,  whether at
maturity or by acceleration  or otherwise,  of the Loan including all principal,
interest  and other  monies  due or that may  become  due  under  the  documents
evidencing  the  Loan  (collectively,  the  "Loan  Documents")  and  the due and
punctual  performance  and observance by Borrower of any other terms,  covenants
and  conditions  of the  Loan  Documents  on the  part of  Borrower  to be kept,
observed or performed  together with all reasonable  legal and other expenses of
collection and enforcement, including payment of the Loan. Each Guarantor hereby
expressly  and  unconditionally   waives  demand,   notice  of  presentment  and
non-payment,  protest and notice of protest,  of said Note and consents that the
time for payment  thereof may be extended by Lender without notice to or further
consent from any Guarantor.

     2. Actions of Lender Do Not Affect Liability. In addition to (but not in
limitation of) all of the foregoing provisions, Lender may take any of the
following actions (with or without notice to any Guarantor) without affecting
the liability of any Guarantor in any way:

          (a) Release, exchange, increase, decrease or surrender all or any part
     of the security held by Lender for the said  obligation,  or substitute new
     security  for all or any portion  thereof,  whether or not the new security
     shall be equal in value with the security substituted.


<PAGE>


          (b) Recast, extend or modify all or any portion of Note.

          (c) Grant waivers, extensions, renewals or other indulgences under any
     of the Loan Documents.

          (d)  Modify  or  amend  any of the  terms,  provisions  or  agreements
     contained in any of the Loan Documents.

          (e) Vary,  exchange,  release or discharge,  wholly or  partially,  or
     delay in or abstain from  perfecting  or enforcing any security or guaranty
     of the Loan Documents by any other person.

          (f) Accept partial  payment or  performance of any of the  obligations
     due under the Loan Documents from the Borrower or any Guarantor.

          (g)  Compromise or make any settlement or other  arrangement  with the
     Borrower or any Guarantor.

     3.  Liability  Unconditional.  Liability  on  this  Guaranty  shall  not be
conditional or contingent upon the pursuance by Lender of whatever remedies that
Lender may have against  Borrower,  nor shall  Lender be required to  foreclose,
exhaust,  or in any other way look for any security  that Lender now has or that
Lender may obtain or acquire in the future.  Lender  shall not be  obligated  or
required to pursue any  remedies it may have against  Borrower,  upon default of
Borrower,  prior to pursuing any remedy against any Guarantor. Not in limitation
of the  generality of the  foregoing,  the liability of any Guarantor  hereunder
shall remain  effective and enforceable even though  Borrower's  liability under
the Loan  Documents may be  unenforceable  or even though  recovery  against the
Borrower  may be barred by a statute  of  limitations  or  otherwise.  Guarantor
waives any  defense  arising  by reason of any  disability  or other  defense of
Borrower  or by  reason of the  cessation,  from any  cause  whatsoever,  of the
liability of Borrower.

     4. Continuing  Liability.  Liability of the Guarantor  hereunder shall be a
continuing  one and  shall  extend to any and all  notes or other  evidences  of
indebtedness that may be given in extension or renewal of the Note.

     5. Representations and Warrants. Each Guarantor hereby represents and
warrants that:

          (a) Barringer Instruments,  Incorporated,  is a New Jersey corporation
     in good  standing and  qualified to do business in New Jersey and all other
     jurisdictions  in which it conducts  business or owns  assets.  Digivision,
     Inc.,  is a California  corporation  in good  standing and  qualified to do
     business in all other  jurisdictions in which it conducts  business or owns
     assets.

          (b) The  execution of this  guaranty by each  Guarantor  has been duly
     authorized  by proper action of its  respective  board of directors and the
     persons  executing  this  guaranty  on behalf of each  Guarantor  have been
     authorized  to act on the  Guarantor's  behalf and to bind each  respective
     Guarantor to the terms hereof.

          (c) Each  Guarantor has the legal capacity to enter into this Guaranty
     and to perform its obligations hereunder.

          (d) This Guaranty  constitutes the legal, valid and binding obligation
     of each Guarantor and is  enforceable  against each Guarantor in accordance
     with its terms, subject to creditors,  rights in general and bankruptcy and
     insolvency laws.


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<PAGE>


          (e) There is no action, suit, proceeding, inquiry or investigation, at
     law or in equity, or before or by any court,  public board or body, pending
     or within the knowledge of any Guarantor threatened, wherein an unfavorable
     decision,  ruling  or  finding  would  (i) to the  extent  not  covered  by
     insurance,  result  in  any  material,  adverse  change  in  the  business,
     financial  condition,  properties  or  operations  of any  Guarantor;  (ii)
     materially  adversely  affect  the  transactions  contemplated  in the Loan
     Documents  or this  Guaranty;  or (iii)  adversely  affect the  validity or
     enforceability of the Loan Documents or this Guaranty.  All authorizations,
     consents  and  approvals  of  governmental  bodies or agencies  required in
     connection  with  the  execution  and  delivery  of  this  Guaranty  or  in
     connection with the performance of each Guarantor's  obligations  hereunder
     have been obtained and will be obtained whenever required hereunder by law.

          (f)  Neither  the  execution  and  delivery  of  this  Guaranty,   the
     consummation  of  the   transactions   contemplated   hereunder,   nor  the
     fulfillment of or compliance with the terms and conditions contained herein
     is  prevented,  limited  by,  conflicts  with or results in a breach of the
     terms, conditions or provisions of any law, rule, regulation,  order of any
     court or governmental agency, or any evidence of indebtedness, agreement or
     instrument  of  whatever  nature to which any  Guarantor  (or any  company,
     corporation or other business entity  controlled by Guarantor or affiliated
     with it) is now a party,  or to which any  Guarantor  or any such entity is
     bound, or constitutes a default under any of the foregoing. Such execution,
     delivery,  consummation  and performance will not result in the creation or
     imposition of any lien,  charge or encumbrance  upon any of the property or
     assets of any Guarantor or any such entity.

          (g) The granting of the credit facility to the Borrower will result in
     material benefits to each Guarantor.

          (h) Neither  this  Guaranty  nor any other  document,  certificate  or
     statement  furnished  to the Lender by or on behalf of the  Borrower or any
     Guarantor  contains  any untrue  statement  of a material  fact or omits to
     state a material fact necessary in order to make the  statements  contained
     herein and therein not misleading or incomplete.

          (i) The  representations  and warranties of the Borrower to the Lender
     were wholly true and accurate when made and are wholly true and accurate as
     of the execution hereof.

     6. Covenants of Guarantor. Each Guarantor hereby covenants and agrees that:

          (a)  Guarantor  guarantees,  unconditionally,  that the Loan and other
     obligations of Borrower under the Loan Documents will be paid and performed
     in accordance with their terms, promptly upon demand of the Lender.

          (b)  Guarantor  shall cause the Borrower to fully  perform and observe
     all of the covenants, agreements and obligations of the Borrower under each
     of the Loan Documents.

          (c) If Guarantor  shall receive any monies,  by reason of the exercise
     of any rights of subrogation or contribution,  prior to the payment in full
     and  performance  of the  Obligations  contained  herein and under the Loan
     Documents,  such amounts  shall be paid by such  Guarantor  directly to the
     Lender.

          (d)  If  Borrower  is  now  or  shall  hereafter  become  indebted  to
     Guarantor,  the amount of each sum and such indebtedness shall at all times
     be  subordinate,  as to lien,  time of payment and in all other respects to
     the amounts  owing to the Lender under the Loan  Documents,  and  Guarantor
     shall not be entitled to enforce or receive  payment thereof until all sums
     owing to the Lender have been paid. Nothing herein contained is intended or
     shall be construed to give Guarantor any right of


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<PAGE>


     subrogation  in or under the Note, or any right to  participate  in any way
     therein, notwithstanding any payments made by Guarantor under the Guaranty.
     The obligations of the Guarantor hereunder shall continue in full force and
     effect until the obligations and all obligations of the Borrower shall have
     been fully paid and performed.

          (e) At all times  during the term of this  Guaranty,  Guarantor  shall
     operate and maintain its assets and  properties in a reasonable  manner and
     keep their property in good repair, and shall not despoil their assets.

          (f) Guarantor shall promptly notify Lender of any material and adverse
     changes in Guarantor's  financial  condition during the period of time that
     the Loan remains outstanding.

          (g)  Guarantor  shall  promptly  notify  Lender  of  any  litigations,
     actions,  proceedings,  claims or  investigations,  pending  or  threatened
     against  Guarantor,  that may materially and adversely affect the financial
     condition of Guarantor.

     7. Events of Default. Any one or more of the following shall constitute an
"Event of Default" hereunder:

          (a)  Failure of any  Guarantor  to perform its  obligations  herein or
     under the terms of the  Revolving  Credit Loan  Agreement,  dated March 13,
     1998, as amended.

     8. Remedies Upon Default.  If any one or more Events of Default shall occur
under this  Guaranty,  then in each case,  the Lender  shall have all rights and
remedies, including but not limited to the right to:

          (a) cause all  amounts  payable  hereunder  and  pursuant  to the Loan
     Documents  to be  immediately  due and  payable,  whereupon  the same shall
     become immediately due and payable;

          (b) take any  other  action  available,  either in law or in equity to
     enforce  performance or collect any amounts due or thereafter to become due
     under this  Guaranty,  or any of the Loan Documents and exercise all rights
     and remedies of the Lender thereunder;

          (c) enforce the  observance of any of the covenants or  obligations of
     any Guarantor under this Guaranty or any of the obligations of the Borrower
     under the Loan Documents.

     9.  Costs  of  Collection.  This  Guaranty  also  includes  all  reasonable
attorneys'  fees and  expenses  and  disbursements  incurred  by  Lender  in the
collection,  enforcement of payment or performance by Borrower of any obligation
of  Borrower  to  Lender,  and in the  collection,  enforcement  of  payment  or
performance  by each  Guarantor  hereunder,  including all  reasonable  expenses
incurred in enforcing all rights under this Guaranty.

     10. No Waiver. Any waiver by Lender on default of Borrower, and any failure
on the part of Lender to enforce its rights against  Borrower,  shall be limited
to that particular instance,  shall not operate or be deemed to waive any future
default  or  defaults,  and shall not  affect  the  absolute  and  unconditional
liability of any Guarantor. Any extensions of time granted by Lender to Borrower
shall not release any Guarantor from its obligations hereunder.

     11.  Indemnification.  Each Guarantor  shall  indemnify and save the Lender
harmless from any loss, claim,  demand or charge  whatsoever  incurred by Lender
arising out of or resulting  from default of the Borrower  under any of the Loan
Documents.


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<PAGE>


     12.  Continuing  Effect.  This  Guaranty  shall  continue  in full  effect,
notwithstanding any insolvency or bankruptcy of the Borrower.

     13. Consent and Waiver By Guarantor.  Each Guarantor hereby consents to all
the terms and provisions of each of the Loan Documents,  as the same may be from
time to time amended or modified. Each Guarantor hereby irrevocably waives:

          (a) Notice of  acceptance  of this Guaranty and notice that credit has
     been extended by the Lender in reliance thereon;

          (b) Notice of any  amendment  or any change in the terms of any of the
     Loan Documents,  or any other present or future agreement relating directly
     or indirectly thereto;

          (c) Notice of any  default  or Event of Default  under any of the Loan
     Documents,  or any other present or future agreement  relating  directly or
     indirectly thereto;

          (d) Demand  for  performance,  observance  of and  enforcement  of any
     provisions,  or any pursuit or exhaustion of any rights or remedies against
     the Borrower,  or any other  Guarantor or obligor who becomes liable in any
     manner for any of the  obligations,  and any  requirements  of diligence or
     promptness  on the  part  of  the  Lender  or any  assignee  of  Lender  in
     connection therewith;

          (e) Diligence,  presentment, protest, notice of dishonor and notice of
     default in the  payment of any amount at any time  payable by the  Borrower
     under or in connection with any of the Loan Documents;

          (f) The benefit of any statute of  limitations  affecting  Guarantor's
     liability hereunder or the enforcement thereof, and agrees that any payment
     of any indebtedness or other act that shall toll any statute of limitations
     applicable  thereto  shall  similarly  operate  to  toll  such  statute  of
     limitations applicable to Guarantor's liability hereunder; or

          (g) The benefit of laws exempting property from levy or execution.

     14. Binding Effect.  Each Guarantor  hereto agrees that this Guaranty shall
bind and inure to the benefit of its successors and assigns.

     15.  Governing Law. This Guaranty shall be governed by the  substantive law
of New Jersey.  Each Guarantor hereby consents to the jurisdiction of the courts
of the State of New Jersey or the federal courts located in the federal district
of New Jersey.

     16. Assignment By Lender.  Lender may, without notice, assign this Guaranty
in whole or in part to a party to whom the Loan is assigned.

     17. Setoff.  In addition to all liens upon,  and rights of setoff  against,
the monies,  securities or other property of each  Guarantor  given to Lender by
law,  Lender shall have a lien upon and a right of setoff  against,  all monies,
securities  and  other  property  of  each  Guarantor  now or  hereafter  in the
possession  of  Lender.  Every  such lien and right of setoff  may be  exercised
without demand upon or notice to any Guarantor. No lien or right of setoff shall
be deemed to have been waived by any act or conduct on the part of Lender, or by
any neglect to exercise  such right of setoff or to enforce such lien, or by any
delay in so doing.  Every right of setoff and lien shall  continue in full force
and effect  until such right of setoff or lien is assigned to Lender as security
for this Guaranty and the Loan,  without reducing or affecting in any manner the
liability of any  Guarantor  under the other  provisions of this  Guaranty.  Any
notes now or hereafter evidencing indebtedness of Borrower to any Guarantor


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<PAGE>


shall be marked with a legend that the same are subject to this  Agreement  and,
if Lender so requests, shall be delivered to Lender.

     18. Notices. All notices, requests and other communication pursuant to this
Guaranty  shall be in writing,  addressed to the Lender at its place of business
first  indicated  above or to the Guarantor at its address first indicated above
or at such other  address as either party may give notice to the other as herein
provided.  Any notice shall be by certified mail, return receipt requested,  and
shall  be  effective  upon  mailing.  If hand  delivered,  the  notice  shall be
effective upon receipt.

     19. Obligations Absolute. The obligations of each Guarantor hereunder shall
be joint, several and absolute.

     20.  Severability.  If any term,  provision,  covenant or condition  hereof
should  be held by a court of  competent  jurisdiction  to be  invalid,  void or
unenforceable,  all other  provisions,  covenants and conditions hereof not held
invalid, void or unenforceable shall continue in full force and effect and shall
in no way be affected, impaired or invalidated thereby.

     21.  Payment  Without  Deduction.  Each  Guarantor  shall make all payments
required hereunder, free of any deductions, and without abatements, deduction or
setoff.

     22. Waiver of Jury Trial.  Each Guarantor  waives any right to a jury trial
in any  litigation in any court with respect to, in  connection  with or arising
out of the Loan or any instrument or document delivered pursuant to the Loan, or
with  respect  to  the  validity,  protection,  interpretation,   collection  or
enforcement of the Loan.


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<PAGE>


     IN WITNESS  WHEREOF,  each  Guarantor  has executed this Guaranty as of the
date first written above.


ATTEST:                                      GUARANTOR:
                                             Barringer Instruments Incorporated,
                                             a Delaware corporation


/s/ Richard S. Rosenfeld                     By:  /s/ Stanley Binder
-----------------------------                     ------------------------------
Richard S. Rosenfeld                         Name:  Stanley Binder
Vice President Finance                       Title:  President




                                             Digivision, Inc.
                                              a California corporation


/s/ Richard S. Rosenfeld                     By:  /s/ Stanley Binder
-----------------------------                     ------------------------------
Richard S. Rosenfeld                         Name:  Stanley Binder
Vice President Finance                       Title:  President




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