EXHIBIT 10.1(B)

                                 PROMISSORY NOTE

$500,000                          Houston, Texas                   June 14, 2000


      Blastco Services Company, a Texas corporation (hereinafter called the
"Company," which term includes any directly or indirectly controlled
subsidiaries or successor entities), for value received, hereby promises to pay
to Industrial Holdings, Inc. (hereinafter called "Holder"), or its registered
assigns, the principal sum of Five Hundred Thousand Dollars ($500,000), together
with accrued interest on the amount of such principal sum, payable in accordance
with the terms set forth below.

                                    ARTICLE I

                                   DEFINITIONS

      For all purposes of this Note, except as otherwise expressly provided or
unless the context otherwise requires: (i) the terms defined in this Article
have the meanings assigned to them in this Article and include the plural as
well as the singular; (ii) all accounting terms not otherwise defined herein
have the meanings assigned to them in accordance with generally accepted
accounting principles as promulgated from time to time by the Association of
Independent Certified Public Accountants; and (iii) the words "herein" and
"hereof" and other words of similar import refer to this Note as a whole and not
to any particular Article, Section or other subdivision.

      "BUSINESS DAY" means each Monday, Tuesday, Wednesday, Thursday and Friday
which is not a day on which banking institutions in Houston, Texas are
authorized or obligated by law or executive order to be closed.

      "EVENT OF DEFAULT" has the meaning specified in Section 3.01.

      "INDEBTEDNESS" of any Person means all indebtedness of such Person,
whether outstanding on the date of this Note or hereafter created, incurred,
assumed or guaranteed, (i) for the principal of, premium on and interest on all
debts of the Person whether outstanding on the date of this Note or thereafter
created for money borrowed by such Person (including capitalized lease
obligations), money borrowed by others (including capitalized lease obligations)
and guaranteed, directly or indirectly, by such Person, or purchase money
indebtedness, or indebtedness secured by property ("Purchase Money
Indebtedness") at the time of the acquisition of such property by such Person,
for the payment of which the Person is directly or contingently liable; (ii) for
all accrued obligations of the Person in respect of any contract, agreement or
instrument imposing an obligation upon the Person to pay over funds; (iii) for
all trade debt of the Person; and (iv) for all deferrals, renewals, extensions
and refundings of, and amendments, modifications and supplements to, any of the
indebtedness referred to in (i), (ii) or (iii) above.

                                    - Ex-4 -
<PAGE>
      "MATURITY DATE", when used with respect to the Note means June 13, 2002
(or such earlier date upon which the Note becomes due and payable).

      "NOTE" means this Promissory Note in the original principal amount of
$500,000.

      "PERSON" means any individual, corporation, partnership, joint venture,
association, joint-stock company, trust, unincorporated organization or
government or any agency or political subdivision thereof.

      "SIGNIFICANT SUBSIDIARY" means at any time, any Subsidiary of the Company
that constitutes a "Significant Subsidiary" of the Company within the meaning of
Rule 1-02 of Regulation S-X under the Securities Act of 1933, as amended.

      "SUBSIDIARY" means a corporation or other entity in which more than 50% of
the outstanding voting stock or equity interests is owned or controlled,
directly or indirectly, by the Company or any combination of the Company and one
or more other Subsidiaries. For the purposes of this definition, "voting stock"
means stock or other interests which ordinarily has voting power for the
election of directors, and equity interests means the right to receive the
profits of the entity, when disbursed, or the assets of the entity upon
liquidation or dissolution.

                                   ARTICLE II
                                    PAYMENTS

      Section 2.01. INTEREST. From the date of this Note through the Maturity
Date, interest shall accrue hereunder on the unpaid outstanding principal sum of
this Note at a rate equal to 9% per annum calculated on the basis of a 360-day
year. All past due amounts of principal and interest shall bear interest at 15%
per annum calculated on the basis of a 360-day year until paid.

      Section 2.02. PAYMENT OF PRINCIPAL AND INTEREST. Subject to Section 2.03
hereof, the principal and unpaid interest of this Note shall be due and payable
in full on the Maturity Date.

      Section 2.03. PREPAYMENTS. At any time before the Maturity Date, the
Company may prepay all or any part of this Note without penalty in whole or in
part. All payments made under this Note shall be applied first to accrued
interest, and the balance, if any, to principal; provided, however, that
interest shall accrue under any remaining principal balance and shall be payable
at the rate provided above.

      Section 2.04. MANNER OF PAYMENT UPON MATURITY. At maturity, payment of
principal and interest on this Note will be made by delivery of checks to Holder
at its address as set forth in this Note or wire transfers pursuant to
instructions from Holder. If the date upon which the payment of principal and
interest is required to be made pursuant to this Note occurs other than on a
Business Day, then such payment of principal and interest shall be made on the
next occurring Business Day following said payment date and shall include
interest through said next occurring Business Day.

                                    - Ex-4 -
<PAGE>
                                   ARTICLE III
                                    REMEDIES

     Section 3.01. EVENTS OF DEFAULT. An "Event of Default" occurs if:

            A. the Company defaults in the payment of the principal or interest
of the Note when such principal or interest becomes due and payable; or

            B. the Company breaches (i) any of its covenants set forth in
Section 4.07 of this Note or (ii) any of its representations, warranties,
covenants or agreements in that certain Stock Purchase Agreement (the "Purchase
Agreement") dated June 13, 2000 but effective as of April 1, 2000 among the
Company, Holder, and Gary H. Martin and William R. Massey (the "Purchasers"); or

            C. the Company or any Significant Subsidiary defaults in the payment
when due (whether by lapse of time, by declaration, by call for redemption or
otherwise) of the principal of or interest on any Indebtedness of the Company or
any Significant Subsidiary (other than the Indebtedness evidenced by the Note or
good-faith disputes with trade creditors) having an aggregate principal amount
in excess of $5,000 and such default remains uncured for a period of 15 days; or

            D. a court of competent jurisdiction enters a final and
non-appealable judgment or judgments against the Company or any Significant
Subsidiary or any property or assets of the Company or any Significant
Subsidiary for the payment of money aggregating $50,000 or more in excess of
applicable insurance coverage; or

            E. a court of competent jurisdiction enters (i) a decree or order
for relief in respect of the Company or any Significant Subsidiary in an
involuntary case or proceeding under any applicable federal or state bankruptcy,
insolvency, reorganization or other similar law or (ii) a decree or order
adjudging the Company or any Significant Subsidiary a bankrupt or insolvent, or
approving as properly filed a petition seeking reorganization, arrangement,
adjustment or composition of or in respect of the Company or any Significant
Subsidiary under any applicable federal or state law, or appointing a custodian,
receiver, liquidator, assignee, trustee, sequestrator or other similar official
of the Company or any Significant Subsidiary or of any substantial part of the
property of the Company or any Significant Subsidiary or ordering the winding up
or liquidation of the affairs of the Company or any Significant Subsidiary; or

            F. the Company or any Significant Subsidiary: (i) commences a
voluntary case or proceeding under any applicable federal or state bankruptcy,
insolvency, reorganization or other similar law or any other case or proceeding
to be adjudicated a bankrupt or insolvent; (ii) files a petition, answer or
consent seeking reorganization or similar relief under any applicable federal or
state law; (iii) makes an assignment for the benefit of creditors; or (iv)
admits in writing its inability to pay its debts generally as they become due;
or

            G. the Company or any Significant Subsidiary (i) merges or
consolidates with or into any other Person; or (ii) the Company or any
Significant Subsidiary dissolves or liquidates; or (iii) the Company or any
Significant Subsidiary sells all or any substantial portion of its assets.

      Section 3.02. ACCELERATION OF MATURITY. This Note and all accrued interest
shall automatically become immediately due and payable if an Event of Default
occurs.

                                    - Ex-4 -
<PAGE>
                                  ARTICLE IV
                                   COVENANTS

      The Company covenants and agrees that, so long as this Note is
outstanding:

      Section 4.01. PAYMENT OF PRINCIPAL AND ACCRUED INTEREST. The Company will
duly and punctually pay or cause to be paid the principal sum of this Note,
together with interest accrued thereon from the date hereof to the date of
payment, in accordance with the terms hereof.

      Section 4.02. CORPORATE EXISTENCE. The Company will do or cause to be done
all things necessary to preserve and keep in full force and effect its corporate
existence, rights (charter and statutory) and franchises.

      Section 4.03. TAXES; CLAIMS; ETC. The Company will, and will cause each
Subsidiary to, promptly pay and discharge all lawful taxes, assessments, and
governmental charges or levies imposed upon it or upon its income or profits, or
upon any of its properties, real, personal, or mixed, before the same shall
become in default, as well as all lawful claims for labor, materials, and
supplies or otherwise which, if unpaid, might become a lien or charge upon such
properties or any part thereof, and which lien or charges will have a material
adverse effect on the business of the Company; PROVIDED, however, that neither
the Company nor any Subsidiary shall be required to pay or cause to be paid any
such tax, assessment, charge, levy, or claim prior to institution of foreclosure
proceedings if the validity thereof shall concurrently be contested in good
faith by appropriate proceedings and if the Company shall have established
reserves deemed by the Company adequate with respect to such tax, assessment,
charge, levy, or claim.

      Section 4.04. MAINTENANCE OF EXISTENCE AND PROPERTIES. The Company will,
and will cause each Subsidiary to, keep its material properties in good repair,
working order, and condition, ordinary wear and tear excepted, so that the
business carried on may be properly conducted at all times in accordance with
prudent business management.

      Section 4.05. COMPANY REPORTS. Within 10 days of a request from Holder,
the Company shall deliver to Holder a copy of its unaudited financial statements
for the most recent month ended prior to such request, which shall include a
balance sheet, an income statement and a statement of cash flow, together with a
certificate from the President of the Company that such financial statements are
true and correct and are in accordance with the books and records of the Company
and present fairly the financial condition of the Company as of the dates, and
for the periods indicated and have been prepared in accordance with generally
accepted accounting principles consistently applied. As soon as available and in
any event within 100 days after the end of each fiscal year of the Company, a
consolidated balance sheet of the Company and its consolidated Subsidiaries as
of the end of such fiscal year and the related consolidated statements of income
and cash flow for such fiscal year, setting forth in each case in comparative
form the figures for the previous fiscal year, all reported by the Company
substantially in accordance with generally accepted accounting principles
consistently applied and audited by independent public accountants.

                                    - Ex-4 -
<PAGE>
      Section 4.06. NOTICE OF DEFAULTS. The Company will promptly notify the
Holder in writing of the occurrence of (i) any Event of Default under this Note,
and (ii) any event of default (or if any event of default would result upon any
payment with respect to this Note) with respect to any Indebtedness as such
event of default is defined therein or in the instrument under which it is
outstanding, permitting holders to accelerate the maturity of such Indebtedness.

      Section 4.07. NEGATIVE COVENANTS. Without the prior written consent of the
Holder, the Company or any Subsidiary will not (i) consolidate or merge with or
sell or transfer all or any portion of its assets to any Person, except that the
Company shall be allowed to sell the assets of its gas measurement business
provided that the proceeds of such sales are used to pay either this Note or the
other promissory notes issued by the Company or the Purchasers pursuant to the
Purchase Agreement and that the Company shall be allowed to sell any other
assets of the Company provided that the proceeds of such sales are used to pay
debt owed by the Company to Persons that are not related to or affiliated with
the Company or the Purchasers, (ii) authorize or effect the payment of dividends
on or the redemption or repurchase of any capital stock of the Company, (iii)
increase the salary of any employee by more than 15% in any given year or hire
an employee at a rate 15% higher than previously paid to employees in similar
positions, (iv) enter into or engage in any transaction or agreement with any
Person related to or affiliated with the Company, or (v) make payments exceeding
$25,000 per month in the aggregate pursuant to any aircraft leases or charges
associated with such aircraft leases, such as fuel or pilot expenses.

      Section 4.08. COMPLIANCE WITH LAWS. The Company will promptly comply with
all laws, ordinances and governmental rules and regulations to which it is
subject.

                                    ARTICLE V
                                  MISCELLANEOUS

      Section 5.01. COLLECTION FEES. If this Note is placed in the hands of an
attorney for collection, and if it is collected through any legal proceedings at
law or in equity or in bankruptcy, receivership or other court proceedings, the
Company hereby undertakes to pay all costs and expenses of collection including,
but not limited to, court costs and the reasonable attorney's fees of Holder.

      Section 5.02. CONSENT TO AMENDMENTS. This Note may be amended, and the
Company may take any action herein prohibited, or omit to perform any act herein
required to be performed by it, if and only if the Company shall obtain the
written consent to such amendment, action or omission to act from the holders of
a majority of the aggregate principal amount of the Note.

      Section 5.03. BENEFITS OF NOTE. Nothing in this Note, express or implied,
shall give to any Person, other than the Company, Holder, and their successors
any benefit or any legal or equitable right, remedy or claim under or in respect
of this Note.

      Section 5.04. SUCCESSORS AND ASSIGNS. All covenants and agreements in this
Note contained by or on behalf of the Company and the Holder shall bind and
inure to the benefit of the respective successors and assigns of the Company and
the Holder.

                                    - Ex-4 -
<PAGE>
      Section 5.05. TRANSFER. This Note is transferable in the same manner and
with the same effect as in the case of a negotiable instrument payable to a
specified person.

      Section 5.06. NOTICES. All notices and communications required or
permitted hereunder shall be in writing and may be given by depositing the same
in the United States mail, addressed to the party to be notified, postage
prepaid and registered or certified with return receipt requested, or by
delivering the same in person to an officer or agent of such party, or sent by
telecopier, at the address or telecopier number as any party hereto shall
specify from time to time.

      Section 5.07. SEVERABILITY CLAUSE. In case any provision in this Note
shall be invalid, illegal or unenforceable in any jurisdiction, the validity,
legality and enforceability of the remaining provisions in such jurisdiction
shall not in any way be affected or impaired thereby; provided, however, such
construction does not destroy the essence of the bargain provided for hereunder.

      Section 5.08. GOVERNING LAW. This Note shall be governed by, and construed
in accordance with, the internal laws of the State of Texas (without regard to
principles of choice of law).

      Section 5.09. USURY. It is the intention of the parties hereto to conform
strictly to the applicable laws of the State of Texas and the United States of
America, +and judicial or administrative interpretations or determinations
thereof regarding the contracting for, charging and receiving of interest for
the use, forbearance, and detention of money (referred to as "Applicable Law").
The Holder shall have no right to claim, to charge or to receive any interest in
excess of the maximum rate of interest, if any, permitted to be charged on that
portion of the amount representing principal which is outstanding and unpaid
from time to time by Applicable Law. Determination of the rate of interest for
the purpose of determining whether this Note is usurious under Applicable Law
shall be made by amortizing, prorating, allocating and spreading in equal parts
during the period of the actual time of this Note, all interest or other sums
deemed to be interest (referred to in this Section as "Interest") at any time
contracted for, charged or received from the Company in connection with this
Note. Any Interest contracted for, charged or received in excess of the maximum
rate allowed by Applicable Law shall be deemed a result of a mathematical error
and a mistake. If this Note is paid in part prior to the end of the full stated
term of this Note and the Interest received for the actual period of existence
of this Note exceeds the maximum rate allowed by Applicable Law, Holder shall
credit the amount of the excess against any amount owing under this Note or, if
this Note has been paid in full, or in the event that it has been accelerated
prior to maturity, Holder shall refund to the Company the amount of such excess,
and shall not be subject to any of the penalties provided by Applicable Law for
contracting for, charging or receiving Interest in excess of the maximum rate
allowed by Applicable Law. Any such excess which is unpaid shall be canceled.

              [THE REMAINDER OF THIS PAGE IS INTENTIONALLY BLANK.]

                                    - Ex-4 -
<PAGE>
      IN WITNESS WHEREOF, the Company has caused this instrument to be duly
executed on the date first above written.

                              BLASTCO SERVICES COMPANY


                              Name:/S/ GARY MARTIN
                              Title: PRESIDENT

Pay to the order of Comerica Bank-Texas, Agent, a Texas banking association with
full recourse, and with full warranty and representation as specified in that
certain Collateral Assignment of Notes from the undersigned to Comerica
Bank-Texas, as Agent.

                              Industrial Holdings, Inc.

                              By:/S/ CHRISTINE A. SMITH
                              Name: Christine A. Smith
                              Title: Executive Vice President

                                    - Ex-4 -