Highway Safety Programs; Model Specifications for Calibrating Units for Breath Alcohol Testers; Conforming Products List of Calibrating Units

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

[Docket No. 94-068; Notice 2]

Highway Safety Programs; Model Specifications for Calibrating

Units for Breath Alcohol Testers; Conforming Products List of

Calibrating Units

AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.

ACTION: Notice; request for comments.

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SUMMARY: This notice amends the Model Specifications for Calibrating

Units for Breath Alcohol Testers by incorporating an alternative

testing procedure using National Institute for Standards and Technology

(NIST) Reference Gas Mixtures (RGMs) for the evaluation of dry gaseous

ethanol calibrating devices and making other changes that were

previously proposed to simplify the Model Specifications and to make

them easier to read. This notice also proposes and seeks comment on a

new alternate procedure for evaluating the accuracy of both wet bath

and dry gas breath alcohol calibrating units using infra-red

spectroscopy. Published with this notice is an amended Conforming

Products List (CPL) of calibrating units that meet the Model

Specifications. This amended list includes five new listings, one wet

bath unit and four dry gas units.

DATES: The amendments to the Model Specifications and the issuance of

the Conforming Products List of calibrating units meeting the Model

Specifications become effective on August 13, 1997. Comments on the

alternate testing procedure using infra-red spectroscopy proposed as an

amendment to the Model Specifications published herein must be received

by October 14, 1997.

ADDRESSES: Comments regarding the alternate testing procedure should

refer to the docket number and the number of this notice and be

submitted (preferably in ten copies) to the NHTSA Docket Section, Rm.

5109, 400 Seventh St., S.W. Washington, D.C. 20590 (Docket hours are

from 9:30 a.m. to 4 p.m.).

FOR FURTHER INFORMATION CONTACT: Dr. James F. Frank, Impaired Driving

Division, Office of Traffic Injury Control Programs (OTICP), NTS-11,

400 Seventh St., SW, Washington, DC 20590. Telephone (202) 366-5593.

SUPPLEMENTAL INFORMATION: On August 18, 1975 (40 FR 36167), NHTSA

published a standard for Calibrating Units for Breath Alcohol Testers.

A Qualified Products List of calibrating units for breath alcohol

testers, of devices which met the standard, was

[[Page 43417]]

first issued on November 30, 1976 (41 FR 53389).

On December 14, 1984, NHTSA issued a notice to convert the

mandatory standards for evidential breath testers and calibrating units

for breath alcohol testers to Model Specifications for such devices (49

FR 48855 and 49 FR 48865, respectively) and to establish a Conforming

Products List (CPL) of evidential breath testers and calibrating units

meeting the Model Specifications. Amendments to the CPL have been

published in the Federal Register since that time. Evidential breath

testers are instruments that measure the alcohol content of deep lung

breath samples with sufficient accuracy for evidential purposes.

Calibrating units provide known concentrations of ethanol vapor for the

calibration or calibration checks of instruments which measure breath

alcohol.

NHTSA published a notice in the Federal Register (59 FR 67377) on

December 29, 1994, amending the Model Specifications for calibrating

units for breath alcohol testers and updating the CPL for calibrating

units. The notice also proposed and sought comments about providing an

alternate testing procedure for evaluating the accuracy and precision

of dry-gas ethanol calibrating units.

Officials who use breath alcohol testers must verify their accuracy

at appropriate intervals during use. The traditional means for ensuring

accuracy has been by checking the breath tester calibration by use of a

``wet bath'' calibrator, a device which provides moist alcohol in air

samples at accurately known concentrations. Dry gas calibrating units

have become available as an alternate means for calibration checking.

A dry gas calibrator produces alcohol-in-inert gas samples (e.g.,

nitrogen or argon) at accurately known concentrations from a compressed

gas cylinder. Dry gas calibrators, like wet bath calibrators, can be

used to calibrate certain types of breath testers, but an evaluation of

their precision and accuracy requires alternate procedures. Today's

notice amends the Model Specifications for Calibrating Units for Breath

Alcohol Testers by incorporating an alternative testing procedure using

National Institute for Standards and Technology Reference Gas Mixtures

for the evaluation of dry gaseous ethanol calibrating devices and

making other changes that were previously proposed to simplify the

Model Specifications and to make them easier to read. Additional minor

changes were made to ensure accuracy and improve clarity of the

document. Also, the term BrAC has replaced the term BAC throughout the

model specifications to ensure consistency with usage recommended in

the Uniform Vehicle Code.

Today's notice also proposes an additional new alternate procedure

for evaluating wet bath and dry gas calibrating units using infra-red

spectroscopy. The agency believes that use of infra-red spectroscopy

will offer several important advantages in the evaluation of both wet

bath and dry gas calibrating units. Comments are sought regarding the

agency's proposal.

A. Comments Received

1. Overview

The agency received two comments in response to the notice of

December 29, 1994: one from Scott Specialty Gas Co. (Scott Gas), a

manufacturer of a dry gas calibrating unit, and one from U.S. Alcohol

Testing (USAT), a manufacturer of an evidential breath test device and

a wet bath calibrating unit that is currently listed on the NHTSA CPL.

Scott Gas was generally supportive of the proposed revisions to the

Model Specifications. USAT stated that it would favor the use of dry

gaseous ethanol calibrating devices when ``it has been adequately

demonstrated that dry-EtOH [calibration units] give results comparable

to those obtained with conventional wet bath simulator calibration

units.''

Neither of the respondents specifically commented on the proposed

revisions to simplify the Model Specifications. As stated in the

notice, these proposed revisions did ``not represent substantive

alterations in the procedures followed or in the criteria used to

determine whether devices meet these model specifications.'' The

proposed revisions have been adopted without change.

Both Scott Gas and USAT raised questions in their comments about

those aspects of the Model Specifications relating to the proposed new

alternate testing procedure for evaluating the accuracy and precision

of dry gas calibrating units. The comments addressed a number of key

issues, including the comparability of wet bath and dry gas calibrating

units and certain specific conditions affecting dry gas calibrating

units. The issues that were contained in the comments are summarized

and discussed below.

2. Comparability Between Wet Bath and Dry Gas Calibrating Units

USAT commented that ``[T]he use of a dry gas EtOH standard makes no

physical sense until it can be demonstrated that the presence of water

vapor in the breath samples analyzed has no effect on the analytical

outcome on the ethanol concentration of the breath samples analyzed by

the [evidential breath tester].''

While it is true that dry gas and human breath differ in moisture

content, NHTSA has found no reason to exclude the use of dry gas

calibrating units solely on this basis. If a calibrating unit (either

wet bath or dry gas) meets the precision and accuracy criteria of the

Model Specifications, the calibrating unit should be considered

acceptable for general use.

Independent research has confirmed the comparability of dry gas and

wet bath calibrating units and the accuracy of dry gas calibrating

units. Kurt M. Dubowski and Natalie A. Essary studied the performance

of dry gas calibrating units and concluded that ``dry gas vapor-alcohol

control [VAC] samples conformed to established formal specifications

and * * * compared favorably with simulator effluents for control tests

of breath alcohol analyzers which are capable of adjusting VAC results

for ambient atmospheric pressure.'' 1 Lance D. Silverman, et

al. reported on the comparability of wet bath and dry gas calibrating

units. These researchers determined that there was substantial

equivalence between both types of calibrating units. Their data ``based

on collection of ethanol in an impinger and titration using a modified

California Department of Health method * * * confirm[ed] the alcohol

content of EBS compressed gases standards by an absolute, wet chemical

method.'' 2

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\1\ Dubowski, K. and N.A. Essary ``Vapor-Alcohol Control Tests

with Compressed Ethanol-Gas Mixtures: Scientific Basis and Actual

Performance.'' Journal of Analytical Toxicology (1996)20, 484.

\2\ Silverman, L.D., Wong, K. and Miller, S. ``Confirmation of

Ethanol Compressed-Gas Standard Concentrations by a NIST-traceable,

absolute chemical method and comparison to wet breath alcohol

simulators.'' Accepted for Publication in the Journal of Analytical

Toxicology, 1997.

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3. Should the Model Specifications Be Expanded To Address Unique

Conditions Affecting Dry Gas Calibrating Units?

USAT challenged the use of dry gas calibrating units based on the

following factors: (a) condensation in the cylinder as a consequence of

low temperatures during shipment; (b) the need to make corrections due

to changes in atmospheric pressure; and (c) the performance of dry gas

calibrators over a range of temperatures and concentrations.

NHTSA has considered these comments carefully and has concluded

that dry gas calibrating units are suitable for evaluation according to

the Model

[[Page 43418]]

Specifications and believes that the Model Specifications are

sufficient to ensure the accuracy and precision of dry gas calibrating

units. However, in light of the concerns raised by USAT, the agency has

amended the procedures for submitting a product for certification. When

a manufacturer submits a product to the agency for testing, it now must

submit also a set of the instructions that are provided to end users.

The instructions must sufficiently describe the procedures to be

followed to protect against condensation in dry gas cylinders that

might occur as a result of freezing during shipment and to correct for

atmospheric pressure.

(a) Condensation in Dry Gas Cylinders as the Result of Freezing

USAT commented that dry gas calibrating units were previously shown

to have a ``memory effect when transported or stored at temperatures

somewhat below room temperature.'' NHTSA acknowledges that dry gas

calibrators could freeze during shipment and this could affect test

results. As a result of freezing, alcohol could condense in the inside

surface of the cylinder. If this were to happen, re-equilibration of

the alcohol with the nitrogen after warming to room temperature could

take a long time. It is possible that the gas in such cylinders might

be used before re-equilibration occurred with the result that samples

would be obtained at incorrect concentrations.

Manufacturers of dry gas calibrating units recommend that, after

receiving the dry gas cylinders, users should warm the cylinders to

room temperature, then lay them down on a flat surface and physically

roll them back and forth for a period of ten minutes to ensure

equilibration of the contents. To test whether this procedure would

ensure that the dry gas calibrators remained accurate, several

cylinders of Lion Laboratories AlcoCal dry gas calibrators were placed

in the freezer compartment of a refrigerator overnight at a temperature

of -15 deg.C, then taken out of the freezer, warmed to room temperature

and rolled on a table top for ten minutes. Data was collected

confirming that tanks that were rolled after freezing gave accurate

results.3

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\3\ Flores, Arthur, ``Dry Gas Calibration Units Report'' U.S.

Department of Transportation Volpe National Transportation Systems

Center, Cambridge MA, September 1996.

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As described in the section on procedures for product submission

included at the end of this notice, when manufacturers submit their

instruments for testing, they are required to submit copies of the

instructions they provide to end users. NHTSA will examine these

instructions to ensure that they provide sufficient information about

this procedure. Products submitted without this information will not be

tested.

(b) The Effect of Variable Atmospheric Pressure on Dry Gas Calibrators

USAT commented that dry gas calibrating units may exhibit a

pressure-dependent concentration effect that wet bath calibrating units

do not. The packaging of a dry gas calibrator compresses a large volume

of an alcohol-in-inert gas mixture into a metal cylinder of only about

one (1) liter. The concentration of the alcohol in the gas is given by

the Ideal Gas Law 4: PV = nRT, where P is the pressure of

the gas, V is the volume, n is the number of moles of gas, R is the gas

constant, and T is the temperature of the gas. The concentration of the

gas is obtained as a function of pressure and temperature:

Concentration = n/V = P/RT.

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\4\ Farrington Daniels & Robert Alberty, ``Physical Chemistry''

3rd Ed., John Wiley & Sons, New York, 1966.

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When a calibration check is performed, some of the gas in the

cylinder is released by operating the release valve. The volume of the

released gas will expand and its pressure will drop until prevailing

atmospheric pressure is reached. The gas is prepared so that the

desired concentration is obtained at normal atmospheric pressure, 760

millimeters of mercury. However, atmospheric pressure varies slightly

from day to day and can change suddenly at times. The most significant

effect comes from high elevations, where prevailing atmospheric

pressure is significantly lower than 760. Atmospheric pressure

corrections are made using an equation derived from the Ideal Gas Law:

C = C760 X P/760, where C is concentration and P is the

prevailing atmospheric pressure.

In order for any calibrating unit to operate properly under such

atmospheric pressures, accurate pressure correction must be made. The

agency has tested the dry gas calibrating units placed on the CPL in

this publication using this pressure correction procedure and has

determined that these devices meet the Model Specifications. The agency

concludes that the pressure dependent concentration effect is

consistent and well established and that pressure correction procedures

suggested by manufacturers are effective and produce accurate results.

As described in the section on procedures for product submission

included at the end of this notice, when manufacturers submit their

instruments for testing, they are required to submit copies of the

instructions they provide to end users. While manufacturers already

provide information on pressure corrections in their instructions to

end users, these Model Specifications have been amended to require that

the instructions include information about how atmospheric pressure

corrections should be made. NHTSA will examine manufacturers'

instructions to ensure that they provide sufficient information about

these pressure correction procedures. Products submitted without this

information will not be tested. NHTSA believes that these procedures

will be effective when used by properly qualified breath alcohol

technicians.

(c) The Performance of Dry Gas Calibrators Over Range of Temperatures

and Concentrations

Throughout its written comments, USAT argues that dry gas standards

should not be accepted because they have not been shown to be

comparable to wet bath standards. USAT argues:

Further substantial equivalence of the dry-EtOH and wet

simulators must be shown over the range of environmental

temperatures and pressures likely to be encountered during normal

field usage of any of the devices appearing on the CPL * * * [and]

over the range of NHTSA tested concentrations * * * throughout the

operating lifetime of the dry gas [calibrating units] * * *

Results of comparative performance of dry-ETOH [calibrating

units] versus wet simulator [calibrating units] need to be publicly

presented in scientific forums and published in the technical

literature to establish a level of confidence that dry gas

[calibrating units] yield substantially equivalent results to those

obtained for decades from conventional wet simulator [calibrating

units].

USAT commented that ``Dry gas EtOH [calibrating units] must be required

to show equivalent performance over the entire range of environmental

conditions used to test wet bath simulator [calibrating units].'' The

agency tests both wet bath and dry gas calibrating units according to

the Model Specifications. The agency believes that the Model

Specifications require testing over an appropriate range of

temperatures and concentrations. Dry gas calibrating units are required

to show equivalent performance over the entire range of environmental

conditions used to test wet bath calibrating units.

[[Page 43419]]

4. Are Dry Gas Calibrating Units Sufficiently Accurate?

USAT states that it would favor use of dry gas calibrating units

when ``it has been adequately demonstrated that dry EtOH [calibrating

units] give results comparable to those obtained with conventional `wet

bath simulator calibration units'.''

The same Model Specifications used to test the accuracy and

precision of wet bath calibrating units are used to ensure the quality

and performance of dry gas calibrating units. All units are tested over

the same range of temperatures and concentrations. All dry gas

calibrating units placed on the CPL in this publication conform to the

Model Specifications. Any unit that fails to meet the requirements of

the Model Specifications would not be included on the agency's list of

conforming products.

5. Miscellaneous Issues

(a) Quality Assurance Plan

Scott Gas recommended that the agency require Quality Assurance

Plans (QAPs) for calibrating units. QAPs are used to provide

information on the correct use, proper maintenance procedures and other

specific requirements of a calibration device. Scott Gas recommended

that the QAP address issues such as NIST traceability, mechanisms for

product coding and traceability, list of proper delivery equipment,

specifications on the containers being submitted for approval, shipping

and storage information, written laboratory certification and

manufacturing procedures, DOT specification documentation on

containers, a specified uncertainty at the 95% confidence level and

shelf life results.

NHTSA strongly endorses the need for quality control in

manufacturing, but believes that this is addressed appropriately by the

manufacturers of these instruments. When calibrating units are used by

law enforcement officials, quality control measures are also taken

under the programs of each state. In transportation workplace testing,

quality control is ultimately handled by the existing requirement for

QAPs for evidential breath testers and alcohol screening devices

(Screeners) which address calibration accuracy. The evidential breath

tester QAPs call for calibration checks using an approved calibrating

unit. If an evidential breath tester or a Screener gives an incorrect

reading when a calibration check or a calibration is conducted, it

suggests that there is an error in the system consisting of the

evidential breath tester (or Screener), the breath alcohol technician,

or the calibrating unit. NHTSA believes that the safeguards already in

place in the QAPs for evidential breath testers and Screeners make it

unnecessary to require an additional QAP specific to the calibrating

unit.

(b) Stability of Dry Gas Calibrators Over Their Operating Life

USAT commented that ``Further substantial equivalence of the dry-

EtOH and wet simulators must be shown over the range of NHTSA tested

concentrations * * * throughout the operating lifetime of the dry gas

[calibrating units] * * *'' Scott Gas also commented that

``presentation of gas manufacturer stability documentation to NHTSA,

before inclusion on the CPL, plus NHTSA evaluation of aged product

should be done in order to assess the ``real life'' performance of the

product.''

The agency's experience indicates that dry gas calibrating units

are normally stable even after years of storage. In addition, NHTSA has

verified that National Institute of Standards and Technology Reference

Gas Mixtures used to evaluate dry gas cylinders remained stable to

within plus-minus0.001 BrAC for a one year period. The

agency has concluded that manufacturers will not be required to provide

stability documentation.

NHTSA shall certify that the CPL does, in fact, reflect calibrating

units which meet the performance criteria set forth in the Model

Specifications. NHTSA reserves the right to test any unit on the CPL

throughout its useful life to ensure that the unit is performing in

accordance with the Model Specifications. In addition, in the section

on procedures for a product submission, included at the end of this

notice, NHTSA requests that users of calibrating units provide both

acceptance and field performance data to NHTSA's Office of Traffic

Injury Control Programs. NHTSA will conduct a special investigation if

information gathered from the field indicates that a device on the CPL

is not performing in accordance with the Model Specifications.

After the recent expansion of the use of dry gas calibrators, one

manufacturer found that the concentration of some dry gas calibrators

had changed from the stated concentrations after weeks or months of

storage. A recall of all cylinders in use was ordered. The problem was

investigated and, after extensive testing it was traced to defects in

certain cylinders and was corrected.

(c) National Institute of Standards and Technology Reference Gas

Mixtures

In the Notice published on December 24, 1994, NHTSA proposed to

revise the Model Specifications to permit use of National Institute of

Standards and Technology Reference Gas Mixtures (NISTRGMs) as reference

samples to evaluate the accuracy of dry gas calibrating units by gas

chromatography.

Use of these dry gas standards allows reliable evaluation of dry

gas calibrators by the gas chromatograph technique. USAT commented

that:

It is rumored that NISTRGMs are manufactured by Scott Specialty

Gases/Scott Medical Products Inc. If true, the NHTSA-proposed

substitution of NISTRGMs to replace wet bath simulator standards for

the testing of any Scott Gas gaseous standards amounts to one

manufacturer certifying itself and claiming the blessing of both

NIST and NHTSA.

The NISTRGMs obtained by the Volpe center were manufactured by Scott

Specialty Gases, but were obtained from and analyzed independently by

the Department of Commerce National Institute for Standards and

Technology (NIST). NIST attested in writing to the accuracy of each

individual cylinder of gas which was obtained by the Volpe Center.

(d) The Comparability of Dry Gas Calibrating Units When Used With a

Variety of Evidential Breath Testing Devices

USAT commented that ``dry gas standards are likely to give

different results when used on [evidential breath testers] based on

different technologies.'' According to USAT, there have been reports

that dry gas calibrating units do not yield the same results for

certain breath testers as wet bath calibrating units. USAT asserts that

a small ``offset'' in test result reportedly occurs when dry gas

calibrators are used for these breath testers compared with wet

calibrators at the same concentration. The offset for fuel cell breath

testers is reported to be -0.002 BrAC when dry calibrators are used to

check calibration of fuel cell evidential breath testers.

Performance requirements contained in NHTSA's Model Specifications

for evidential breath testers require that these instruments be

accurate to 0.005 or 5% of test BrAC, whichever is greater,

with a standard deviation not greater than 0.004. The performance

requirements for calibrating units require the devices to be accurate

to within 0.002 BrAC of the test BrAC with relative standard deviation

of 2%. Any offset associated with a particular calibrator is not

considered.

[[Page 43420]]

Agency testing indicates that dry gas calibrating units can be used

with infra-red and fuel cell breath testers.5 The agency

tested four fuel cell testers, one fuel cell/infra-red combination

tester with readout from the fuel cell sensor, and one infra-red tester

to obtain wet dry comparison data. The instruments tested were:

\5\ Flores, Arthur, ``Dry Gas Calibrating Units Report'', U.S.

Department of Transportation, Volpe National Transportation Systems

Center, Cambridge, MA, September, 1996.

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Life Loc, Inc. PBA 3000 and PBA 3000X (FC)

CMI, Inc. Intoxilyzer 400 (FC)

Intoximeters, Inc. AlcoSensor IV (FC)

National Draeger, Inc. Breathalyzer 7410-II (FC)

Intoximeters, Inc. EC-IR (FC/IR)

CMI, Inc. Intoxilyzer 5000 (IR)

Measurements were made alternately using first a sample from a wet bath

calibrator, then a sample from a dry gas calibrator. Five measurements

of each type of sample were made on each of the testers. The wet

calibrator solutions were prepared to produce the same concentrations

as the corresponding dry gas. Wet samples were produced using RepCo

Marketing simulators (wet bath calibrating units). Dry samples were

obtained from dry gas calibrating units from Scott Specialty Gases,

Inc. (0.04 BrAC) and Gateway Airgas, Inc. (0.04 and 0.088 BrAC). The

concentration of the Scott gas was verified by Intoximeters, Inc. and

the concentration of the gas from Gateway Airgas was verified by infra-

red spectroscopy at the Volpe center. The factory calibrations of the

breath testers were not adjusted. The reliability of the ``true value''

of the wet or dry standards can be taken as known values to within

about 0.001 BrAC. Thus, the true value of a wet sample or a

dry sample at 0.040 BrAC can be expected to be correct to within about

0.001 BrAC.

The differences between wet bath and dry gas calibrating units were

negligible when the comparisons were made using infra-red breath

testers. These differences were around 0.002 BrAC and are not

noticeable unless comparisons are made carefully, because this value is

near the accuracy limit of the calibrating units.

The differences observed when comparisons were made using fuel cell

type breath testers, the next most widely used type of breath tester,

were more noticeable, especially at high alcohol levels. The offset for

fuel cell breath testers averaged somewhat less than 4% of the nominal

BrAC when dry gas calibrators were used to check calibration of fuel

cell evidential breath testers. The offsets found for the breath

testers ranged from -0.0014 BrAC to 0.0026 BrAC when compared at the

0.04 BrAC level, and from -0.0020 to 0.0052 when compared at the 0.088

level. The standard deviations for the wet and dry data were in the

fourth decimal place except in one instance when a value of 0.002 was

obtained, which was still acceptable. These results indicate that the

offsets are small and reproducible enough that reliable corrections can

be applied to ensure accurate test results. The offsets observed cannot

be assumed to arise only from the inherent differences in measurement

of moist samples compared to the measurement of dry samples since there

are also uncertainties of 0.001 in the true concentration

of wet bath or dry gas calibration unit vapors.

Offsets must be indicated by manufacturers in their instructions to

end users. Manufacturers are required to include their instructions in

a submission of a calibrating unit for testing. The agency will examine

the instructions to ensure that they provide sufficient information on

offsets necessary for certain breath testers. Products submitted

without this information will not be tested.

Gas Chromatograph breath testers depend on extensive surface

interaction with the sample being analyzed, and the greatest

differences between dry and wet standards are seen with this type of

breath tester. In its laboratory, NHTSA has found that the effects are

not stable. They vary with type and condition of resolving column used.

Accordingly, NHTSA believes that dry gas calibrating units should not

be used with gas chromatograph breath testers because the results are

too variable. The agency will include a footnote on the CPL concerning

the use of dry gas standards with gas chromatograph evidential breath

testers, indicating that the agency does not recommend the use of dry

gas calibrating units with gas chromatograph evidential breath testers.

B. Procedures for a Product Submission

Testing of calibrating units submitted by manufacturers to these

Model Specifications will continue to be conducted by the DOT Volpe

National Transportation Systems Center (VNTSC). Tests will continue to

be conducted semi-annually or as necessary. Manufacturers wishing to

submit calibrating units for testing must apply to NHTSA for a test

date (Office of Traffic Injury Control Programs, NTS-11, NHTSA, 400

Seventh Street, S.W., Washington, D.C. 20590). Normally, at least 30

days will be required from the date of notification until the test can

be scheduled. One week prior to the scheduled initiation of the test

program, the manufacturer will deliver at least one unit of the device

to be tested to: VNTSC, DTS-75, 55 Broadway, Kendall Square, Cambridge

MA 02142. The manufacturer shall be responsible for ensuring that the

unit is operating properly. If the manufacturer wishes to submit a

duplicate, backup unit, it may do so.

When a manufacturer delivers a device to be tested, it shall also

deliver to VNTSC specifications and drawings that fully describe the

unit and the Operator's Manual and Maintenance Manual normally supplied

with purchase of the equipment. Proprietary information will be

respected. (See 49 CFR Part 512, regarding the procedures by which

NHTSA will consider claims of confidentiality.)

The manufacturer shall also deliver the instructions that will

accompany the device when it is sold. The instructions shall include

information about the procedures to be followed to protect against

possible condensation that might occur as a result of freezing during

shipment and to correct for atmospheric pressure. The instructions

shall also include information about any offsets that may apply to the

use of a particular type of breath tester. NHTSA will examine these

instructions to ensure that they provide sufficient information about

these matters. Products submitted without this information will not be

tested.

The manufacturer will have the right to check the calibrating unit

between arrival in Cambridge and the start of the test, and to ensure

that the calibrating unit is in proper working condition but will have

no access to it during the tests. Any malfunction of the calibrating

unit which results in failure to complete any of the tests

satisfactorily will result in a finding that it does not conform to the

Model Specifications. If a unit fails to conform, it may be resubmitted

for testing after appropriate corrective action has been taken.

On the basis of these results, NHTSA will publish a Conforming

Products List (CPL) identifying the calibrating units that conform to

the Model Specifications.

Retesting of units will be conducted when necessary. NHTSA intends

to modify and improve these Model Specifications as new data and

improved test procedures become available. (The test procedures may be

altered in specific instances, if necessary, to meet the unique design

features of a calibrating unit). If these Model Specifications are

modified, notification will be provided in the Federal Register. If

NHTSA determines that retesting to the modified

[[Page 43421]]

specifications is necessary, a manufacturer whose equipment is listed

on the CPL will be notified to resubmit the equipment for testing to

the modified specification only.

NHTSA will certify that the CPL does, in fact, reflect calibrating

units which meet the performance criteria set forth in the Model

Specifications. NHTSA reserves the right to test any unit on the CPL

throughout its useful life to ensure that the unit is performing in

accordance with the Model Specifications.

If at any time a manufacturer plans to change the design of a

calibrating unit currently on the CPL, the manufacturer shall submit

the proposed changes to the Office of Traffic Injury Control Programs

for review. Based on this review, NHTSA will decide whether the change

will require retesting of the unit. Normally, such retesting will be

accomplished the next time testing is performed. Guidance to

manufacturers on considerations governing this decision are available

from NHTSA's OTICP, upon request.

OTICP will be the point of contact for information about acceptance

testing and field performance of equipment already on the list. When it

is available, NHTSA requests that users of calibrating units provide

both acceptance and field performance data to OTICP. Information from

users will be used to: (1) help NHTSA determine whether units continue

to perform according to the NHTSA Model Specifications and (2) ensure

that field use does not indicate excessive breakdown or maintenance

problems.

If information gathered indicates that a device on the CPL is not

performing in accordance with the Model Specifications or demonstrates

problems involving the device, NHTSA will direct VNTSC to conduct a

special investigation. This investigation may include visits to users

and additional tests of the unit obtained from the open market. If the

investigation indicates that the units actually sold on the market are

not meeting the Model Specifications, then the manufacturer will be

notified that the unit may be removed from the list. In this event the

manufacturer shall have 30 days from the date of notification to reply.

Based on the VNTSC investigation and any data provided by the

manufacturer, NHTSA will decide whether the unit should remain on the

list. Upon resubmission, the manufacturer must submit a statement

describing what has been done to overcome the problems that led to the

dropping of the unit in question from the list.

C. Infra-red Spectroscopy

In this notice, NHTSA is proposing an alternate procedure which

uses infra-red spectroscopy for the evaluation of dry gas units (see

Appendix A). It is proposed as an amendment to the Model Specifications

for Calibrating Units published in this notice. In infra-red

spectroscopy, the wet bath or dry gas sample to be analyzed is passed

into a chamber through which infra-red radiation is transmitted. The

wavelength of the transmitted radiation is chosen so that some of it is

absorbed by alcohol. According to the Beer-Lambert Law of absorption of

radiation,6 the amount of energy absorbed by the sample in

the chamber is proportional to the concentration of the alcohol in the

sample. By measuring the amount of radiation transmitted when the

sample chamber is empty and the amount transmitted when the sample is

present, the concentration of the alcohol in the sample can be

determined.

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

\6\ Farrington Daniels & Robert Alberty, ``Physical Chemistry''

3d Ed. John Wiley & Sons, New York, 1966.

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

The agency believes that use of infra-red spectroscopy will offer

several important advantages. First, the technique can be used to

evaluate both wet bath calibrating units and dry gas calibrating units

because surface interactions do not effect the analysis. Second,

standards used in the evaluations can be prepared at the Volpe Center,

eliminating the necessity of obtaining standards from an outside

source.

D. Comments

Interested persons are invited to comment on the proposed alternate

procedure described in this notice. It is requested, but not required

that 10 copies be submitted. Comments must not exceed 15 pages in

length (49 CFR 553.221). Necessary attachments may be appended to those

submissions without regard to the 15 page limit. This limitation is

intended to encourage commentors to detail their primary arguments in a

concise fashion.

All comments received before the close of business on the comment

closing date indicated above will be considered, and will be available

for examination in the docket at the above address, both before and

after that date. To the extent possible, comments filed after the

closing date will also be considered. However, the amendments to the

Model Specifications may be published at any time after that date, and

any comments received after the closing date and too late for

consideration with regard to the action will be treated as suggestions

for future revisions to the Specifications. NHTSA will continue to file

relevant material in the docket after the closing date as it becomes

available. It is recommended that interested persons continue to

examine the docket for new material.

Those persons who desire to be notified upon receipt of their

comments in the docket should enclose a self-addressed stamped postcard

in the envelope with their comments. Upon receiving the comments, the

docket supervisor will return the postcard by mail.

E. Conforming Products List

The Conforming Products List (CPL), which appears as Appendix B to

this notice, lists the calibrating units that have been retested to

date at the lower BACs (i.e., at 0.020, 0.040, 0.080, and 0.160) and

found to conform to the Model Specifications reprinted herein. The CPL

also lists devices that have not been tested at these lower BAC levels,

but which were listed on a previous CPL for calibrating units (58 FR

26030) on the basis that they were tested and found to conform to the

earlier model specifications when tested at BAC levels 0.050, 0.100 and

0.150. These devices have been identified with an asterisk.

This CPL also includes five new listings: four dry-gas calibrating

units and one wet-bath calibrating unit. The dry gas units include:

Model EBSTM'' Gaseous Ethanol Breath Standard submitted by

Scott Specialty Gases, Inc. of Plumsteadville, PA; the Ethanol Breath

Alcohol Standard submitted by Gateway Airgas (previously known as A.G.

Specialty Gas Company, or Acetylene Gas Company) of St. Louis, MO; the

AlcoCal Breath Alcohol Standard submitted by Lion Laboratories, plc of

Cardiff, Wales, UK; and Compressed ethanol-in-nitrogen submitted by

Liquid Technology Corporation of Orlando, FL. All of the dry-gas

calibrating units were tested using the alternate procedure that uses

the NISTRGM. The new wet-bath unit is Model 3402C submitted by RepCo

Marketing, Inc., of Raleigh, NC.

In consideration of the foregoing, NHTSA amends the Model

Specifications for Calibrating Units, as last published in the Federal

Register on December 29, 1994 (59 FR 67377), as set forth below. NHTSA

proposes to further amend these Model Specifications, as set forth in

Appendix A.

[[Page 43422]]

Model Specifications for Calibrating Units for Breath Alcohol Testers

1.0 Purpose and Scope

These specifications establish performance criteria and methods for

testing of calibrating units which provide known concentrations of

ethanol vapor for the calibration or calibration checks of breath

alcohol testers. The results of this testing are intended for use in

the conformance testing for the maintenance of a Conforming Products

List for calibrating units.

2.0 Definitions

2.1 Conformance testing. Testing to check the conformance of a

product with these model specifications in advance of and independent

of any specific procurement action.

2.2 Concentration units. Blood alcohol concentration: grams

alcohol per 100 milliliters blood or grams alcohol per 210 liters of

breath in accordance with the Uniform Vehicle Code, Section 11-

903(a)(5).7 BrAC is often used to indicate that the

measurement is a breath measurement, i.e. gram alcohol per 210 liters

of breath.

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

\7\ Available from National Committee on Uniform Traffic Laws

and Ordinances, 405 Church Street, Evanston, IL 60201.

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

2.3 Relative Standard Deviation (RSD). The ratio of the standard

deviation (SD) of a series of measurements to the mean of the series

expressed as a percentage:

RSD=(SD/Mean) x 100 percent

2.4 Standard Deviation (SD). A common indication of precision in

the measurement of the concentration of a succession of N vapor

samples.

SD={Sum (Xi-Xm)\2\/(N-1)}\1/2\

where Xi=a single measurement result;

Xm=the average of the measurements;

N=the number of measurements made in the test.

2.5 Systematic Error (SE). An indication of the accuracy of the

measurement of the concentration of a succession of vapor samples.

SE=Xm-test BrAC

2.6 Least Squares Fit Calibration Curve. A line fitted to a number

of measurement pairs, one the independent value (X) and the other the

dependent value (Y), over a measurement range.

The fitted line is of the form: Y=a+bX, where intercept,

a=Ym-bXm, and slope,

b=(SumXiYi-NXmYm)/

(SumXi2-nXm2).

3.0 Tests and Requirements

If the BrAC of the CU is fixed, perform the tests at the fixed

BrAC; otherwise, prepare the CU for testing at 0.08 BrAC except as

otherwise required in Test 1 below. Each of the tests require 10

measurements to three decimal places using the test procedure specified

in 3.1. The CU will be operated according to the manufacturer's

instructions. Unless otherwise specified, the tests will be performed

in the absence of drafts and at prevailing normal laboratory

temperature, humidity, and barometric pressure. Performance

requirements are:

-0.002 BrAC SE + 0.002 BrAC; RSD 2%

Test 1. Precision and Accuracy. Test at each specified BrAC.

Test 1.1: 0.020 BrAC

Test 1.2: 0.040 BrAC

Test 1.3: 0.080 BrAC

Test 1.4: 0.160 BrAC

Test 2. Ambient Temperature. Use a temperature chamber controllable

to 2 deg.C. Soak the CU at the specified temperature for 1

hour, being careful to prevent drafts on the device, then test at that

temperature.

Test 2.1: 10 deg.C

Test 2.2: 30 deg.C.

Test 3. Input Power. If the CU is powered by nominal voltages of

120 volts AC or 12 volts DC, condition the device for one half hour at

the appropriate input voltage specified below, then test at that

voltage. Monitor the input power with a voltmeter accurate to

2% full scale in the range used and re-adjust the voltage,

if necessary. If the voltage is AC, conduct tests 3.1 and 3.2. If the

voltage is DC, conduct tests 3.3 and 3.4.

Test 3.1: 108 Volts/AC

Test 3.2: 123 Volts/AC

Test 3.3: 11 Volts/DC

Test 3.4: 15 Volts/DC

Test 4. Electrical Safety Inspection. Examine the CU for protection

of the operator from electrical shock. Examine for proper use of input

power fuses, and verify that there are no exposed male connectors at

high potential. Determine that overheating does not occur during

operation and that undue fire hazards do not exist.

3.1 Test Procedure (Original, Wet-bath)

Equipment and Supplies: Gas Chromatograph capable of complete

resolution of ethanol in test samples, with heated gas sampling valve.

Water bath thermostated at 34 deg.C 0.1 deg.C. Glass

Reference Sample Bottles (300 ml capacity or greater) with Stopper and

Inlet and Outlet Air Hoses (see Figure 1). Hoses should be about 1/8''

OD Teflon tubing. Reference Ethanol Solutions prepared using class A

glassware and American Chemical Society reagent grade ethanol or USP

grade ethanol. The purity of the ethanol used shall be compared with

the National Institute of Standards and Technology (NIST) Standard

Reference Material for ethanol. Use the value of Harger, et al., for

the partition ratio for concentration of ethanol in head space to

concentration in solution at 34 deg.C, Ka/w = 0.000393 8 to

prepare two solutions which, when thermostated at 34 deg.C, produce

head space ethanol vapor concentrations that bracket the test BrAC by

no more than 20%. Small Air Pump for bubbling air through

reference solutions (see Figure 1).

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

\8\ RN Harger, BB Raney, EG Bridwell, MF Kitchel, J. Biol. Chem.

183, 197-213 (1950). Additional data from Harger in a private

communication (see 49 FR 48869).

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

Step 1. Prepare the Gas Chromatograph for measurement of vapor

samples. Adjust instrument temperatures, gas flows, detector, and

recording device for optimum response for ethanol. Prepare the CU for

use according to manufacturer's instructions.

Step 2. Fill two reference solution bottles to \3/4\ full with

above reference solutions. Insert stopper assemblies with bubble line

and alcohol vapor line in place and put bottles in the water bath with

water level up to the stopper. Connect air pump to bubble line. Connect

alcohol vapor line to gas chromatograph sampling valve inlet fitting.

Allow 1 hour for temperature equilibrium to be achieved.

Step 3. Turn on air pump which has been pre-set to pump air through

the reference solution bottle-gas chromatograph sampling assembly at a

rate just sufficient to thoroughly flush the system in 10 seconds.

After flushing is complete, allow the sample to relax to atmospheric

pressure, then inject the reference sample onto the gas chromatograph

column. In this way, obtain 5 chromatograms of one of the reference

solution head space ethanol vapors.

Step 4. Thoroughly flush the sample loop with vapors from the CU

device, while avoiding over-pressurizing of the sampling system. To

prevent condensation of alcohol, warm the transfer line if necessary.

Allow the sample to relax to atmospheric pressure, then inject the

sample onto the column. In this way, obtain 10 ethanol chromatograms

using the CU device.

Step 5. Repeat step 3 using the second reference solution.

Step 6. Calculations. Peak height to BrAC conversion factor. For

each ethanol peak obtained in step 2 and step

[[Page 43423]]

5, calculate a conversion factor for ethanol concentration by dividing

the equivalent BrAC of the vapor sample by the peak height obtained for

that sample. From the ten samples, obtain the mean and the RSD of the

conversion factors. If the RSD obtained fails to meet the criteria for

RSD in 3.0, perform necessary troubleshooting and repeat the procedure

from Step 1. Use the mean of the conversion factors to calculate the

BrAC for each of the 10 ethanol peaks obtained in step 4. Calculate the

mean, the RSD, and the systematic error of the experimental BrACs.

BILLING CODE 4910-59-P

Figure 1. Wet Bath Reference Sample Set-up. Sample lines \1/8\''

Teflon. The bubble line should extend at least 4 inches below

surface of the solution. The length of the alcohol vapor line from

the headspace to the gas chromatograph should be minimized.

[GRAPHIC] [TIFF OMITTED] TN13AU97.000

BILLING CODE 4910-59-C

3.2 Test Procedures (for dry gas Calibrating Units): Alternate Test

Method Using National Institute of Standards and Technology Reference

Gas Mixtures (NISTRGMs) in Place of Wet Bath Reference Samples

The following alternate method for the evaluation of dry gaseous

ethanol calibration devices is presented.

Additional required material: For the alternate method for

evaluation of dry gaseous ethanol calibration devices, the following

will be required: Four cylinders of National Institute of Standards and

Technology ethanol-in-inert gas Technical Reference Gas Mixtures

(NISTRGMs) which span the BrAC range 0.01 to 0.16.

Alternate Procedure for evaluation of dry gaseous ethanol

calibration devices. This procedure substitutes the use of NISTRGMs in

place of the wet bath reference samples when evaluating dry gas CUs.

Step A1. Connect one of the NISTRGM cylinders to the inlet of the

gas chromatograph sampling valve and pass reference gas through the

sampling system at a rate just sufficient to thoroughly flush the

system in about 10 seconds. Allow the sample to relax to atmospheric

pressure, then inject the sample onto the column. In this way, obtain 5

chromatograms of the reference gas.

Step A2. Repeat Step A1 for each of the four NISTRGM reference gas

mixtures.

Step A3. Calculate the RSD of the concentration divided by peak

height data obtained in Step A1 and Step A2. If the calculated RSD

meets the criteria of 3.0, calculate the slope and intercept of the

least squares fit calibration line for conversion of peak height to

BrAC. Using the average peak height of each NISTRGM and the slope and

intercept data, calculate the concentration of each NISTRGM. If the

resulting concentrations are within the stated accuracy of the NISTRGM,

proceed to Step A4.

Step A4. Connect the calibrating device to the inlet of the gas

chromatograph sampling system and allow the calibrating device gas to

flow at a rate just sufficient to thoroughly flush the sampling system

in about 10 seconds. Allow the sample to relax to atmospheric pressure,

then inject the sample onto the column. In this way, obtain 10

chromatograms of the calibrating device gas.

Step A5. Calculations. Using the peak height data obtained in Step

A4 and intercept and slope data obtained in Step A3, calculate the BrAC

for each of the 10 peak heights. Calculate the mean, RSD, and

systematic error of the calculated BrACs.

Authority: 23 U.S.C. 402; delations of authority at 49 CFR 1.50

and 501.

Issued: August 7, 1997.

James Hedlund,

Associate Administrator for Traffic Safety Programs.

Appendix A--Proposed Alternate Procedure Using Infra-Red Spectroscopy

This appendix presents an alternate procedure using infra-red

spectroscopy that is suitable for evaluating vapor samples from either

wet-bath CUs, or from dry-gas CUs.

[[Page 43424]]

3.3 Proposed Test Procedures (for dry gas or wet bath calibrating

units).

3.3.1 General. General. The method uses the Beer-Lambert Law of

absorption of radiant energy by fluids

I = Io X e-abc

Where:

Io is the energy entering the sample chamber of a

spectrophotometer containing the sample to be analyzed.

I is the energy transmitted from the sample chamber.

a is the absorptivity of the sample.

b is the radiation path length of the sample chamber.

c is the concentration of the sample in the sample chamber.

A convenient form of the Beer-Lambert law is

Ln(Io/I) = abc

where the term (Ln(Io/I), the logarithm of the ratio of

incident to transmitted energy, is called the absorbance of the sample.

In the procedure described below, the terms a and b are treated as a

single quantity, ab, and the term c is BrAC.

3.3.2 Test Procedure.

Equipment and Supplies. Infra-red Spectrophotometer with sample

chamber that can be heated to above 40 deg. C. A non-dispersive

instrument with appropriate band pass filters and configured to measure

breath alcohol samples, such as an infra-red evidential breath tester

listed on the NHTSA Comforting Products List for evidential breath

testers may be used. The detector voltage of the instrument must be

accessible for measurement. The sampling hoses of the device may be

altered for more convenient processing of test samples. Water bath

thernostated at 34 deg.C 0.1 deg.C. Glass Reference Sample

Bottles (300 ml capacity or greater) and Stoppers with Bubble and

Alcohol Vapor lines (see Figure 2). Reference Ethanol Solutions

prepared using Class A glassware and American Chemical Society reagent

grade ethanol or USP grade ethanol. The purity of the ethanol used

shall be compared with the National Institute of Standards and

Technology (NIST) Standard Reference Material for ethanol. Use the

value of Harger, et al., for the partition ratio for concentration of

ethanol in head space to concentration in solution at 34 deg. C,

Ka/w = 0.0003932 to prepare two aqueous alcohol

solutions which bracket the test BrAC by no more than 20%.

A cylinder of inert Flushing Gas, which is optically clear in the

absorption region used for measurement. This gas will be used to flush

the sample chamber of the spectrophotometer and to deliver reference

headspace vapors and wet bath sample vapors into the sample chamber.

Pressure regulating valve with teflon delivery hose for controlling

flow and delivery of flushing gas.

Step B1. Prepare the spectrometer for measurement of vapor samples.

Prepare the CU for use according to manufacturer's instructions.

Step B2. Fill a reference sample bottle to \3/4\ full with water

and two reference sample bottles to \3/4\ full with the above reference

solutions. Insert stopper assemblies ensuring that the end of the

bubble line reaches to at least 4 inches below the surface of the

solution, then place the bottles in the water bath with water level up

to the stopper. Allow 1 hour for temperature equilibrium to be

achieved.

Step B3. Connect the bubble line of the sample bottle containing

water only to the flushing gas valve and the vapor line to the

spectrophotometer inlet and flush the sample chamber with water vapor

and obtain the detector voltage reading. Then flush the detector

chamber with flushing gas only and obtain the detector reading. Repeat

2 times to obtain 3 sets of readings. If the CU being evaluated is a

wet bath device, skip this step and proceed to Step 4.

Step B4. In the manner of Step 3, obtain 5 sets of detector

readings using one of the reference alcohol solution bottles.

Step B5. In the manner of Step 3, obtain 10 sets of detector

readings from the CU being evaluated. If the CU is a wet bath device,

use the flushing gas fill the sample chamber, operating the device

according to manufacturer's instructions. If the CU device is a dry gas

device, fill the sample chamber according to manufacturer's

instructions.

Step B6. Repeat Step 5 using the other reference alcohol solution

bottle.

Step B7. Repeat Step 3.

Step B8. Calculations. For each measurement pair, I0 is

the detector voltage obtained for the flushing gas alone in the sample

chamber and I is the voltage obtained for the flushing gas with

reference sample or test sample in the sample chamber corrected for

water vapor absorption, i.e.; the detector voltage obtained for

headspace reference samples at 0.000 BrAC. Use the average of 6 voltage

readings obtained for the water samples for the correction for water

vapor absorption (I=Isample-Iwater). In the case

of wet bath device samples, there is no correction for water vapor

absorption. If the detector is biased, I will be the difference between

the bias voltage and the above voltage.

Calulate the absorbance of each of the 10 reference samples. Divide

each absorbance by the corresponding BrAC of the sample. Obtain the

mean (which is the factor ab), SD, and RSD for the 10 ratios. If the

RSD is more than 2%, trouble shoot the procedure and repeat.

Calculate the absorbance for each of the 10 CU test samples. Divide

each by the ab factor to obtain the BrAC for each of the 10 CU samples.

Obtain the mean, SD, RSD, and SE.

BILLING CODE: 4910-59-P

[[Page 43425]]

Figure 2. Equipment set-up. Bubble and sample lines \1/8\'' teflon,

minimized length. Depth of bubble line into reference solution at

least 4''. The alcohol vapor line from the headspace to the IR

specrophotometer should be minimized.

[GRAPHIC] [TIFF OMITTED] TN13AU97.001

BILLING CODE: 4910-59-C

Appendix B--Conforming Products List of Calibrating Units for Breath

Alcohol Testers [Manufacturer and Calibrating Unit].\1\

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

\1\ Infra-red (IR) and fuel cell breath testers may be

calibrated with either wet-bath or dry-gas CUs. However, it is

inadvisable to use dry gas CUs when calibrating gas chromatograph

EBTs.

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

1. CMI, Inc., Owensboro, KY:

Toxitest II

2. Federal Signal Corporation, CMI, Inc., Minturn, CO:

Toxitest Model ABS120*

3. Gateway Airgas, Inc. (Formerly known as AG Specialty Gas, and

Acetylene Gas Company), St. Louis, MO.

Ethanol Breath Alcohol Standard (a dry gas standard).

4. Guth Laboratories, Inc., Harrisburg, PA:

Model 34C Simulator \2\

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

\2\ Several variations of the Model 34C Simulator have also been

submitted to NHTSA for evaluation and meet these Model

Specifications. They are: Model 34C Cal DOJ; Model 34-C-FM; and 34C-

NPAS.

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

Model 3412

Model 10-4

Model 1214

5. Intoximeters, Inc., St. Louis, MO:

Alco Breath Alcohol Standard* (a dry gas standard)

6. Lion Laboratories, plc, Cardiff, Wales, UK (a subsidiary of CMI,

Inc.)

AlcoCal Gas Standard (a dry gas standard).

7. Liquid Technology Corporation, Orlando, FL

Alcohol-in-Nitrogen Calibrating Unit (a dry-gas

standard).

8. Luckey Laboratories, Inc., San Bernadino, CA:

Simulator*

9. National Draeger, Inc., Durango, CO.

Mark II-A

10. PLD of Florida, Inc., Rockledge, FL:

BA 500

11. Protection Devices, Inc., U.S. Alcohol Testing, Inc., Rancho

Cucamonga, CA:

LS34 Model 6100*

12. Repco Marketing, Inc., Raliegh, NC:

AS-1

Model 3402C

13. Scott Specialty Gases, Inc., Plumsteadville, PA

Model EBS TM Gaseous Ethanol Breath Standard (a

dry-gas standard).

14. Smith & Wesson Electronic Co., Springfield, MA:

Mark II-A Simulator*

15. Systems Innovation, Inc., Hallsteaed, PA

True-Test MD 901*

16. U.S. Alcohol Testing, Rancho Cucamonga, CA:

Alco-Simulator 2000*

Alco--Simulator 61000

* Instruments marked with an asterisk (*) meet the Model

Specifications in 49 FR 48864 (December 14, 1984), i.e. instruments

tested at 0.050, 0.100, and 0.150). Instruments not marked with an

asterisk meet the model specifications detailed in this notice, and

were tested at 0.020, 0.040, 0.080, and 0.160 BrAC.

[FR Doc. 97-21331 Filed 8-12-97; 8:45 am]

BILLING CODE 4910-59-P