REPLACEMENT PROMISSORY NOTE

                            Revolving Line of Credit
                                  Variable Rate

                                 March 14, 2000


Borrowers:  Merit  Medical  Systems,  Inc.,  Merit  Holdings,  Inc.,  and Sentir
            Semiconductor, Inc.

Lender: Zions First National Bank

Amount: $35,000,000.00

Maturity: July 31, 2006


         For value received,  Borrowers promise to pay to the order of Lender at
its  Commercial  Banking  Department  in  Salt  Lake  City,  Utah,  the  sum  of
thirty-five million dollars  ($35,000,000.00) or such other principal balance as
may be outstanding  hereunder in lawful money of the United States with interest
thereon calculated and payable as provided herein.

         This  Replacement  Promissory  Note shall be a revolving line of credit
under which Borrowers may repeatedly draw and repay funds, so long as no default
has occurred  hereunder or under the Amended and Restated Loan  Agreement  dated
August 11, 1999,  between Lender and Borrowers (as amended or otherwise modified
from  time  to  time,  the  "Loan  Agreement")  and so  long  as the  aggregate,
outstanding principal balance at any time does not exceed the Reducing Available
Borrowing  Base (as  defined in the Loan  Agreement).  Disbursements  under this
Replacement Promissory Note shall be made in accordance with the Loan Agreement.

         In connection  with each request for an advance under this  Replacement
Promissory Note, the applicable Borrower shall specify whether the advance shall
bear interest  based on the Prime Rate (as defined  below) or the LIBOR Rate (as
defined  below)  and, if the LIBOR Rate is  selected,  the  applicable  Interest
Period (as defined below).  The  specification  made by such Borrower may not be
changed without consent of Lender. If no specification is made by such Borrower,
the advance shall bear interest based on the Prime Rate.

         Interest on  advances  based on the Prime Rate shall be  calculated  as
follows:

         1.       Interest  shall be at a variable rate computed on the basis of
                  a three  hundred  sixty (360) day year as  follows:  the Prime
                  Rate of Lender from time to time in effect plus the Prime Rate
                  Performance Percent (as defined below) per annum,  adjusted as
                  of the date of any change in the Prime Rate.

         2.       The Prime Rate  Performance  Percent  shall be  determined  as
                  follows:



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<PAGE>

                           (a) If the  Performance  Pricing Ratio (as defined in
                  the Loan  Agreement)  is equal to or greater than three to one
                  (3.0:1), the Prime Rate Performance Percent will be zero (0).

                           (b) If the  Performance  Pricing Ratio is equal to or
                  greater  than two to one  (2.0:1)  but less than  three to one
                  (3.0:1),  the Prime  Rate  Performance  Percent  will be minus
                  fifteen-hundredths (-.15).

                           (c) If the Performance Pricing Ratio is less than two
                  to one  (2.0:1),  the Prime Rate  Performance  Percent will be
                  minus thirty-five hundredths (-.35).

                           The  Prime   Rate   Performance   Percent   shall  be
                  determined  based  upon the most  recent  quarterly  or annual
                  financial  statements  of Borrowers  provided  pursuant to the
                  Loan  Agreement  and shall be  adjusted as of the first day of
                  the month  following the month in which Borrowers are required
                  to  deliver  such  reports  to  Lender  pursuant  to the  Loan
                  Agreement.

         3.       Prime Rate  means an index  which is  determined  daily by the
                  published  commercial loan variable rate index held by any two
                  of the following banks: Chase Manhattan Bank, Wells Fargo Bank
                  N. A.,  and Bank of  America N. T. & S. A. In the event no two
                  of the above  banks  have the same  published  rate,  the bank
                  having the median rate will establish Lender's Prime Rate. If,
                  for any  reason  beyond  the  control  of  Lender,  any of the
                  aforementioned  banks becomes  unacceptable as a reference for
                  the purpose of determining the Prime Rate used herein,  Lender
                  may, five days after posting  notice in Lender's bank offices,
                  substitute  another  comparable  bank  for the one  determined
                  unacceptable.  As used in this  paragraph,  "comparable  bank"
                  shall   mean  one  of  the  ten   largest   commercial   banks
                  headquartered in the United States of America. This definition
                  of  Prime  Rate  is to be  strictly  interpreted  and  is  not
                  intended to serve any purpose other than providing an index to
                  determine the variable  interest  rate used herein.  It is not
                  the lowest  rate at which  Lender may make loans to any of its
                  customers, either now or in the future.

         Interest on  advances  based on the LIBOR Rate shall be  calculated  as
         follows:

         1.       Interest  shall be at a rate  computed on the basis of a three
                  hundred sixty (360) day year equal to the LIBOR Rate of Lender
                  for  the  applicable  Interest  Period  plus  the  LIBOR  Rate
                  Performance Percent (as defined below).

         2.       The LIBOR Rate  Performance  Percent  shall be  determined  as
                  follows:

                           (a) If the  Performance  Pricing Ratio (as defined in
                  the Loan  Agreement)  is equal to or greater than three to one
                  (3.0:1),  the LIBOR Rate  Performance  Percent will be one and
                  sixty-five hundredths (1.65).

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<PAGE>

                           (b) If the  Performance  Pricing Ratio is equal to or
                  greater  than two to one  (2.0:1)  but less than  three to one
                  (3.0:1),  the LIBOR Rate  Performance  Percent will be one and
                  five-tenths (1.50).

                           (c) If the Performance Pricing Ratio is less than two
                  to one (2.0:1), the LIBOR Rate Performance Percent will be one
                  and four-tenths (1.40).

                           The  LIBOR   Rate   Performance   Percent   shall  be
                  determined  based  upon the most  recent  quarterly  or annual
                  financial  statements  of Borrowers  provided  pursuant to the
                  Loan  Agreement and shall remain in effect for the  applicable
                  Interest Period.

         3.       The LIBOR Rate  applicable  to any  Interest  Period means the
                  rate per annum  quoted by Lender as its LIBOR Rate.  The LIBOR
                  Rate  shall be  related  to quotes  for the  London  Interbank
                  Offered  Rate from the British  Bankers  Association  Interest
                  Settlement  Rates,  Lasser Marshall Inc., or other  comparable
                  services for the applicable  Interest Period.  This definition
                  of  LIBOR  Rate  is to be  strictly  interpreted  and  is  not
                  intended to serve any purpose other than providing an index to
                  determine  the interest  rate used  herein.  The LIBOR Rate of
                  Lender may not  necessarily  be the same as the quoted  London
                  Interbank Offered Rate quoted by any particular institution or
                  service applicable to any Interest Period.

         4.       Banking  Business  Day means any day  other  than a  Saturday,
                  Sunday or other day on which  commercial banks in the State of
                  Utah are  authorized  or  required to close and a day on which
                  dealings in dollar  deposits are also carried on in the London
                  Interbank market and banks are open for business in London.

         5.       Dollars  and the  sign  "$" mean  lawful  money of the  United
                  States.

         6.       Interest Period means, with respect to any LIBOR Rate advance,
                  the  period  commencing  on the date such  advance is made and
                  ending,  as  the  applicable   Borrower  may  select,  on  the
                  numerically  corresponding  day in the first,  second,  third,
                  sixth, twelfth, twenty-fourth,  thirty-sixth, forty-eighth, or
                  sixtieth  calendar  month  thereafter,  except  that each such
                  Interest  Period that  commences on the last Banking  Business
                  Day of a calendar  month (or on any day for which  there is no
                  numerically  corresponding  day in the appropriate  subsequent
                  calendar month) shall end on the last Banking  Business Day of
                  the appropriate  subsequent calendar month;  provided that all
                  of the foregoing  provisions  relating to Interest Periods are
                  subject to the following:

                           (a)      No  Interest  Period may  extend  beyond the
                  termination of the Loan Agreement;

                           (b)      No  Interest  Period may  extend  beyond the
                  aforesaid  Maturity  Date or such  later  date to  which it is
                  extended; and



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<PAGE>

                           (c)      If an  Interest  Period  would  end on a day
                  that is not a Banking Business Day, such Interest Period shall
                  be  extended  to the next  Banking  Business  Day unless  such
                  Banking Business Day would fall in the next calendar month, in
                  which event such Interest  Period shall end on the immediately
                  preceding Banking Business Day.

         7.       Notwithstanding   any  other  provision  in  this  Replacement
                  Promissory  Note, if the adoption of any applicable law, rule,
                  or  regulation,  or any change  therein,  or any change in the
                  interpretation or  administration  thereof by any governmental
                  authority, central bank, or comparable agency charged with the
                  interpretation  or  administration  thereof,  or compliance by
                  Lender  with any request or  directive  (whether or not having
                  the  force of law) of any such  authority,  central  bank,  or
                  comparable  agency  shall make it unlawful or  impossible  for
                  Lender to maintain or fund  advances  based on the LIBOR Rate,
                  then  upon  notice to  Borrowers  by  Lender  the  outstanding
                  principal  amount of the  advances  based on the  LIBOR  Rate,
                  together with interest accrued thereon, shall, at the election
                  of Lender, be (1) immediately converted to an advance based on
                  Prime Rate;  (2) repaid  immediately  upon demand of Lender if
                  such change or compliance  with such request,  in the judgment
                  of Lender,  requires immediate repayment; or (3) repaid at the
                  expiration  of the last  Interest  Period to expire before the
                  effective date of any such change or request.

         8.       Notwithstanding  anything to the  contrary  herein,  if Lender
                  determines (which determination shall be conclusive) that:

                           (a)  Quotations  of interest  rates for the  relevant
                  deposits  referred to in the  definition of LIBOR Rate are not
                  being  provided in the  relevant  amounts or for the  relative
                  maturities for purposes of determining the LIBOR Rate; or

                           (b)  The  LIBOR  Rate does not  accurately  cover the
                  cost to Lender of making or maintaining  advances based on the
                  LIBOR Rate,  then Lender may give notice thereof to Borrowers,
                  whereupon   until   Lender   notifies   Borrowers   that   the
                  circumstances  giving rise to such suspension no longer exist,
                  (1) the  obligation  of Lender to make  advances  based on the
                  LIBOR Rate shall be suspended;  and (2) Borrowers  shall repay
                  in full the then outstanding  principal amount of each advance
                  based on LIBOR Rate together with accrued interest thereon, on
                  the last day of the then current Interest Period applicable to
                  such advance,  or, at Borrowers' option,  convert the advances
                  based on LIBOR  Rate to  advances  based on Prime  Rate on the
                  last day of the then current  Interest  Period  applicable  to
                  such advance.
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<PAGE>

         On or before the last day of the applicable  Interest  Period for which
an advance has been made,  the  applicable  Borrower  shall specify  whether the
outstanding  balance  owing  on  the  advance  shall  bear  interest  after  the
applicable Interest Period based on the Prime Rate or the LIBOR Rate and, if the
LIBOR Rate is selected,  the applicable  Interest Period. The specification made
by  such  Borrower  may  not  be  changed  without  consent  of  Lender.  If  no
specification is made by such Borrower, the advance shall bear interest based on
the Prime Rate.


         Principal  and  interest on  advances  based on the Prime Rate shall be
payable as follows:  Interest accrued is to be paid monthly commencing September
1, 1999 and on the same day of each month  thereafter.  All principal and unpaid
interest shall be paid in full on July 31, 2005.

         Principal  and  interest on  advances  based on the LIBOR Rate shall be
payable as follows:  Interest accrued is to be paid monthly commencing September
1, 1999 and on the same day of each month  thereafter and on the last day of the
Interest  Period.  All principal and unpaid  interest shall be paid in full upon
the earlier of maturity of the applicable Interest Period or July 31, 2005.

         As to all advances, whether based on the Prime Rate or the LIBOR Rate:

         1.       Interest  shall  accrue from the date of  disbursement  of the
                  principal  amount or portion  thereof until paid,  both before
                  and after  judgment,  in  accordance  with the terms set forth
                  herein.

         2.       All payments  shall be applied  first to accrued  interest and
                  the remainder, if any, to principal. Lender may apply payments
                  to Prime Rate based or LIBOR Rate based  advances in any order
                  determined by Lender in its sole discretion.

         3.       Notwithstanding anything to the contrary herein, all principal
                  and unpaid interest shall be paid in full on July 31, 2005.

         4.       Upon default in payment of any principal or interest when due,
                  whether due at stated maturity, by acceleration, or otherwise,
                  all  outstanding  principal  shall bear  interest at a default
                  rate from the date when due until paid,  both before and after
                  judgment, which default rate shall be three percent (3.0%) per
                  annum above the Prime Rate.

         If, at any time prior to the  maturity of this  Replacement  Promissory
Note, this  Replacement  Promissory  Note shall have a zero balance owing,  this
Replacement  Promissory  Note shall not be deemed  satisfied or  terminated  but
shall remain in full force and effect for future draws  unless  terminated  upon
other grounds.

         Borrowers  may  prepay  all or any  portion  of all  Prime  Rate  based
advances  at any time  without  penalty.  Any  prepayment  of a LIBOR Rate based
advance  shall be  subject to a  prepayment  fee if the  Original  LIBOR Rate is
greater than the Current LIBOR Rate on the  prepayment  date. The prepayment fee
shall be an amount  equal to the  prepaid  principal  amount  multiplied  by the
product of the Original LIBOR Rate less the Current LIBOR Rate multiplied by the
number of years and fractional portion of a year remaining until maturity of the
Interest  Period.  Current LIBOR Rate means the LIBOR Rate in effect on the date
the prepayment is made for the Interest  Period from that prepayment date to the
date of maturity of the  Interest  Period.  Original  LIBOR Rate means the LIBOR
Rate in effect on the date the LIBOR Rate based  advance  which is being prepaid
was made for the Interest  Period  selected by the applicable  Borrower for that
advance.  Any prepayment received by Lender after 2:00 p.m. mountain standard or
daylight time  (whichever  is in effect on the date the  prepayment is received)
shall be deemed received on the following Banking Business Day.

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<PAGE>

         This  Replacement  Promissory  Note is made in accordance with the Loan
Agreement and is secured by the collateral identified in and contemplated by the
Loan Agreement.

         If default occurs in the payment of any principal or interest when due,
or if any Event of Default (as defined in the Loan  Agreement)  occurs under the
Loan Agreement,  time being the essence hereof,  then the entire unpaid balance,
with  interest as  aforesaid,  shall,  at the election of the holder  hereof and
without notice of such election, become immediately due and payable in full.

         If this  Replacement  Promissory  Note becomes in default or payment is
accelerated,  Borrowers agree to pay to the holder hereof all collection  costs,
including reasonable attorney fees and legal expenses,  in addition to all other
sums due hereunder.

         This  Replacement  Promissory  Note is  issued  in  replacement  of the
promissory  note dated August 11, 1999 issued by the  Borrowers to Lender in the
original principal amount of $28,000,000.00.

         All  obligations of Borrowers  under this  Replacement  Promissory Note
shall be joint and several.

         Borrowers  and all  endorsers,  sureties and  guarantors  hereof hereby
jointly and severally waive presentment for payment,  demand, protest, notice of
protest,  notice of protest and of non- payment and of dishonor,  and consent to
extensions of time, renewal, waivers or modifications without notice and further
consent to the release of any  collateral  or any part  thereof  with or without
substitution.

                                   Borrowers:

                                   Merit Medical Systems, Inc.


                                   By:
                                   Title:


                                   Merit Holdings, Inc.


                                   By:
                                   Title:


                                   Sentir Semiconductor, Inc.


                                   By:
                                   Title:


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