ccl report no. 268 c) study of long term ...a. test panels. aluminum (alloy 2024) panels 2-1/2"...

AD

CCL REPORT NO. 268

C) FINAL REPORT

STUDY OF LONG TERM PACKAGING OF ETHYLFNE GLYCOL ANTIFREEZE

BY

JAMES H. CONLEY

JULY 1969 4.1:

THIS DOCUMENT HAS BEEN APPROVED FOR PUBLIC RELEASEAND SALE; ITS DISTRIBUTION IS UNLIMITED

U. S. ARMY ABERDEEN RESEARCH & DEVELOPMENT CENTEFCOATING & CHEMICAL LABORATORY

Aberdeen Proving GroundMaryland

COLOR ILLUSTRATION'Z RMSPRODUCEDrIN BLACK A, WHITE

iUSTIEI' AT :G4

BY

I L

DDC AVAILABILITY NOTICE

Qualified requesters may obtain copies of this report from DefenseDocumentation Center, Cameron Station, Alexandria, Virginia 22314.

THE FINDINGS IN THIS REPORT ARE NOT TO BE CONSTRUED AS AN OFFICIALDEPARTMENT OF THE ARMY POSITION, UNLESS SO DESIGNATED BY OTHERAUTHORIZED DOCUMENTS.

DESTROY THIS REPORT WHEN IT IS NO LONGER NEEDED. DO NOT RETURN ITTO THE ORIGINATOR.

BestAvailable

Copy

t'

CCL REPORT NO. 268

FINAL REPORI

STUDY OF LONG TERM PACKAGING OF ETHYLENE GLYCOL ANTIFREEZE

BY

JAMES H. CONLEY

JULY 1969

AMCMS CODE NO. 5025.11.803

DEPARTMENT OF THE ARM) PROJECT NO.IGO62105A109

U.S. ARMY ABERDEEN RESEARCH & DEVELOPMENT CENTERCOATING AND CHEMICAL LABORATORY

ABERDEEN PROVING GROUNDMARYLAND

THIS DOCUMENT HAS BEEN APPROVED FOR PUB' IC RELEASE

AND SALE; ITS DISTRIBUTION IS UNLIMITED

UNCLASS I FIED

i

COLOR ILLUSTRATION 4-1; RCDUCEDIN BLACK AP.D WHITE;

ABSTRACT

The object of this study was to investigate conditions which would

effect long term packaging of ethylene glycol antifreeze. Factors in-vestigated were ph, dilution, different inhibitor systems and differentmetals.

Aluminum and tin-coated steel panels were partially immersed inethylene glycol solutions contained in test jars at room temperaturesfor a period of ten years. Inhibitors used in this study included borax,borax/glycol condensate, mercaptobenzothiazole, and the sodium salt ofmercaptobenzothiazole. pH values ranging from 6 to 10.5 were used.Test solutions contained 0%, 3% and 66-2/3% water.

No system tested was adequate for 10 years storage. All systemsexhibited corrosion in the liquid phase and/or the vapor phase.

II

TABLE OF CONTENTS

Page No.

TITLE PAGE................................................

ABSTIRACT .................................................... I

INTROUUCTION.................................................

DETAILS OF TEST ...............................................- 2

RESULTS OF TEST .................................. 2 - 3

REFERENCES...................................................3- 4

DISTRIBUTION LIST .................................. 5 - 6

APPENDIX A .................................................. 7

Tables I - 11..............................................7 - 11

APPENDIX B .................................................. 12

Photographs 1 - 35 ......................... .... 13 - 20

DD FORM 1473 .......................... 21

I. INTRODUCTION

Coating & Chemical Laboratory was directed by Army Materiel Commandto investigate improved antifreeze compounds.

Federal Specification O-A-548, Type I 3ntifreeze which is specifiedfor Army use in TB-750-651 is composed of undiluted ethylene glycol withborax as an inhibitor. As packaged it has an acidic pH (below 7.0) andtends to cause corrosion of tin containers in long term storage. Thismaterial is used in conjunction with 0-I-490a, Inhibitor, Corrosion,Liquid Cooling System. One of the constituents of 0-I-490a is mercapto-benzothiazole (MBT) which greatly enhances the inhibitive properties ofborax in ethylene glycol mixtures which have been diluted for vehicleuse. However, chemically, MBT is an acid, and was found to rapidlycorrode the tin containers when incorporated directly into undilutedO-A-548 antifreeze packages. The Army, therefore, uses a two packageantifreeze system, which is logistically undesirable.

This study was initiated primarily to study conditions which mightpermit the incorporation of O-A-548 and 0-I-490a into a one packageantifreeze system. Preliminary data on this study were presented inCCL Report Nos. 86 and 100. These data showed that under specifiedconditions ethylene glycol could be packaged with MBT and stored forshort periods in both aluminum and tin coated steel containers.

This present report contains data derived from the study since thetwo year inspection.

II. DETAILS OF TEST

A. Test Panels.

Aluminum (alloy 2024) panels 2-1/2" by 3", were prepared byabrading with 320A carborundum paper and steel wool (00 Grade), rinsingwith hot ethyl alcohol and drying in an oven at 210°F.

Tin coated steel panels, 2-1/2" x 3" were prepared by lightlyabrading with steel wool (00 Grade), rinsing in hot ethyl alcohol anddrying in an oven at 210F. The edges of these panels were then dippedin an non-crystalline hydrocarbon wax so that steel edges would not beexposed.

B. Test Jars.

The glass jars used in the test were 14-1/2 ounce screw captype, approximately 3" in diameter and 4" deep. The jars were closedwith screw caps containing lacquered paper pulp liners.

I

C. Ethylene Glycol.

Ethylene glycol used in the tests was "purified" grade, FisherScientific Company. This glycol contained less than 0.5% water.

D. Inhibitors.

1. Borax - The borax used was sodium tetraborate, decahydrate,C.P. It analyzed 101%, calculated as borax, the excess percentage beingdue to the loss of water of hydration.

2. Borax-glycol condensate - This material was prepared inaccordance with the procedure outlined in CCL Report No. 81. It analyzed14.0 + 1.0% sodium tetraborate (by weight).

3. Mercaptobenzothiazole - Eastman Kodak 2-mercaptobenzothiazole"practical" grade, was used.

4. Sodium salt of mercaptobenzothiazole - R. T. Vanderbilt's

"NACAP", which is a 50% water solution of sodium mercaptobenzothiazole,was used in the tests in amounts corresponding to the quantity of MBTused.

E. Tests Conducted.

1. Test solutions - Thirty-five test solutions used in this

study are listed in Tables I and II. A pH of 10.5 was attained by the

addition of 5.ON aqueous sodium hydroxide.

2. Test procedures - Approximately 200 ml. of solution was

placed in each jar. The metal test panel was approximately one halfimmersed. This permitted inspection of panels exposed to both theliquid phase and the vapor phase. The screw caps were firmly tightenedand the jars stored on a shelf at room temperature.

3. Inspection - One set of duplicate panels were removed intwo month intervals up to 8 months for inspections. The duplicate setof panels were left undisturbed for a total of 24 months storage andinspected. The panels were then placed back in the test jars and leftundisturbed for a total of 10 years. The final inspection Included inthis study was made after 10 years storage.

III. RESULTS OF TEST

A. Effect of dilution on tin-coated steel.

Results of inspections up to 8 months and 2 years are includedin CCL Report Nos. 86 and 100, respectively. Results in Table I and thephotographs show all undiluted samples exhibit heavy corrosion both inthe vapor phase and liquid phase. Tests with 97% glycol and 3% water

2

(Test Nos. 6 and 11) were better than the undiluted samples but were notas good as the tests with 66-2/3% water (Test Nos. 12 to 23A). Thisshows that dilution decrea.es corrosion on tin-coated steel.

B. Effect of dilution on aluminum.

Results of the effect of dilution on aluminum in Table II and

the photographs show that dilution increased corrosion in nearly everycase. One exception was noted with 2-1/4% borax-glycol condensate, 1/2%NACAP at pH 10.5.

C. Effect of pH.

Increasing the pH of undiluted glycol to 10.5 increased thevapor phase corrosion of aluminum in every caje with only a slight differ-

ence in the liquid phase corrosion. Increasirg the pH to 10.5 at 3%dilution decreased the corrosion of tin-coated steel but at 66-2/3% dilu-

tion the increased pH increased corrosion.

D. Comparison of borax-glycol condensate.

Borax-glycol condensate was slightly better than borax in

66-2/3% dilution low pH tests in the liquid phase and in the high pH

tests with tin-coated steel. Borax was better than the condensate in thehigh pH test with 1/2% NACAP at 3% dilution (Table II, Test Nos. 27 and28).

E. Comparison of MBT and its sodium salt.

The sodium salt of MBT (NACAP) was better than MBT in almostevery case. In Test Nos. 8 and 11 with 97% glycol, 2-1/4% borax and3% water at pH 10.5 the MBT was better than the sodium salt.

F. Best ove-all inhibitor combination.

In choosing a single inhibitor combination from this groupwhich would be best on both metals, borax, MBT, and 3% water at pH 10.5would be the best. At 66-2/3% dilution the condensate with NACAP at pH10.5 is the best. Even these would not be considered satisfactory forlong term storage due to the presence of some corrosion either in thevapor phase or the liquid phase. All corrosion is more severe after 10years storage and in the same order as reported after 2 years storage.

IV. REFERENCES

1. Authority, AMC Program Directive.

2. Federal Specification 0-1-490, Inhibitor, Corrosion, Liquid CoolingSystem.

3

3. Federal Secification O-A-548a, Antifreeze, Ethylene Glycol, Inhibited.

4. CCL Report No. 81, Development of an Operational Preservative HydraulicBrake Fluid, August 1959.

5. CCL Report No. 86, Study of a Newly Developed Inhibitor for EthyleneGlycol in Storage, October 1959.

6. CCL Report No. 100, Storage of Ethylene Glycol with Various Inhibitors,14 March 1961.

4

DISTRIBUTION LIST FOR AMCMS CODE NO. 5025.11.803

Department of Defense No. of Copies

Defense Documentation CenterCameron Station 20Alexandria, Virginia 22314

Department of the Army - Technical Service

Commanding GeneralU. S. Army Materiel CommandATTN: AMCRD-GFWashington, D. C. 20315

Continental Army CommandDepartment of the Army 3Fort Monroe, Virginia 23351

Commanding GeneralU. S. Army Tank-Automotive CommandATTN: Mr. J. P. JonesWarren, Michigan 48090

Commanding OfficerFrankford ArsenalATTN: L7000-64-4 I

Library IPhiladelphia, Pennsylvania 19137

Commanding OfficerU.S. Army Materials & MechanicsResearch Center 2ATTN: Technical Information CenterWatertown, Massachusetts 02172

Commanding OfficerYuma Proving GroundArizona 85364

Commanding GeneralU. S. Army Weapons CommandATTN: AMSWE-RDR 2Rock Island, Illinois 61200

Commanding OfficerU. S. Army Chemical Research & Development LaboratoriesATTN: LibrarianEdgewood Arsenal, Maryland 21040

5

DISTRIBUTION LIST CONTINUED

No. of Copies

Commanding OfficerU. S. Army Mobility Equipment Researchand Deve'opment CenterATTN: Technical Documents Center 2Fort Belvoir, Virginia 22060

Commanding OfficerRock Island ArsenalATTN: Laboratory 9320Rock Island, Illinois 61200

Commanding OfficerU. S. Army Ballistic Research LaboratoriesATTN: Mr. R. Eichelberger I

Mr. J. Sperrazza IAberdeen Proving Ground, Maryland 21005

Technical LibraryAberdeen Proving Ground, Maryland 21005 2

Air Force Systems CommandATTN: STLO 2Bldg 314Aberdeen Proving Ground, Maryland 21005

Department of the Navy

Department of the Navyc/o Navy LiaisonAberdeen Proving Ground, Maryland 21005

Department of the NavyChief, Bureau of Naval WeaponsWashington, D. C. 20360

Other 'Government Agencies

NASA Scientific and TechnicalInformation Facility

P. 0. Box 33 3College Park, Marylard 20740

Federal Aviation Administration800 Independence Avenue S. W.ATTN: Administrative Standards Division (MS-l0) 2Washington, D. C. 20590

6

APPENDIX A

TABLE I

Results of 10-Year Inspection Tin-Coated Steel Panels

Photo Inhibitor Dilution, Solution

No. Combination % water Results Appearance

None Undiluted Very heavy vapor phase corrosion. Very rusty

pH 4.90 Liquid phase full of holes.

2 2-1/2% Undiluted Mod-heavy vapor phase corrosion Very rusty

Borax, Tin completely removed in liquid

pH 5.68 phase. Steel shows intergranularcorrosion.

3 2-1/2% Undiluted Pitting in vapor phase. Heavy Very rustyBorax-Glycol rusting at interface. Tin par-

Condensate tially removed in liquid phase.pH 5.55 Some intergranular corrosion.

4 2-1/4% Undiluted Heavy vapor phase corrosion. Very rusty

Borax, 1/4% Liquid phase black and pitted.MBT, pH 5.65

5 2-1/4% Undiluted Heavy vapor phase corrosion. Very rustyBorax-Glycol Liquid phase black and pitted.Condensate1/4% MBT,pH 5.55

6 None 3 Heavy vapor phase corrosion. Tin Very rustypH 5.35 removed from panels in liquid

phase. Steel perforated withholes.

7 2-1/4% 3 Very heavy vapor phase corrosion. Very rustyBorax, 1/2% Very heavy liquid phase corrosion.NACAP,pH 6.00

8 2-1/4% 3 Slight vapor phase corrosion. Trace of

Borax, 1/4% Liquid phase okay. sedimentMBT, pH 10.5

9 2-1/4% 3 Very heavy vapor phase corrosion. Very rustyBorax-Glycol Excessive pitting in liquid phase. (black)

Condensate1/4% MBT,pH 5.75

7

TABLE I - (Continued)


No. Combination % water Results Appearance

10 2-1/4% 3 Vapor phase stained. Tin com- Very slightBorax-Glycol pletely removed in liquid phase. yellowCondensate, Steel shows intergranular corro- sediment.1/4% MBT, sion.pH 10.5

11 2-1/2% 3 Moderate vapor phase corrosion. Very slightBorax Liquid phase coated with crystals sediment.Condensate but no evidence of pits.1/2% NACAP,pH 10.5

12 None 66-2/3 Very heavy vapor phase corrosion. Very rustypH 4.55 Panel completely dissolved except

under the wax in the liquid phase.

13 2-1/2% 66-2/3 Slight vapor phase corrosion. ClearBorax Liquid phase okay.pH 7.82

14 2-1/2% 66-2/3 Light scattered pitting. Liquid ClearBorax-Glycol phase stained.Condensate,pH 7.85

15 2-1/4% 66-2/3 Heavy vapor phase corrosion. YellowBorax, Liquid phase stained and coated, sediment1/4% MBTpH 7.72

16 2-1/2% 66-2/3 Scattered pitting. Filiform ClearBorax corrosion in liquid phase.pH 10.5

17 2-1/4% 66-2/3 Very heavy vapor phase corrosion. RustyBorax, Heavy pitting and rusting in1/4% MBT, liquid phase.pH 10.5

17A 2-1/4% 66-2/3 Very slight vapor phase corrosion. SlightBorax Tin completely removed in liquid sediment1/4% MBT phase. Steel show intergranularpH 10.5 corrosion.

8

TABLE I - (Continued)


No.. Combination % water Results Appearance

18 2-1/4% 66-2/3 Very slight vapor phase corrosion. SlightBorax-Glycol Tin completely removed in liquid yellowCondensate phase. Steel shows intergranular sediment1/4% MBT, corrosion.pH 7.55

19 2-1/4% 66-2/3 Vapor phase okay. Tin partly SlightBorax-Glycol removed in liquid phase. Some sedimentCondensate intergranular corrosion. (white)1/4% MBT

20 2-1/4% 66-2/3 Slight vapor phase corrosion. Heavy whiteBorax, Slight corrosion and stains in sediment1/2% NACAP liquid phase.pH 7.88

21 2-1/4% 66-2/3 Slight vapor phase corrosion. Very slightBorax, Light etching with tin removed sediment1/2% NACAP, in one spot.pH 10.5

22 2-1/4% 66-2/3 Very slight vapor phase corrosion. Heavy lightBorax-Glycol Moderate-heavy stain in liquid yellowCondensate, phase. sediment1/2% NACAP,pH 7.88

22A 2-1/4% 66-2/3 Slight vapor phase corrosion. Moderate-Borax-Glycol, Heavy corrosion at interface on Heavy yellowCondensate, one side. Liquid phase okay. sediment1/2% NACAP,pH 7.88

23 2-1/4% 66-2/3 Slight vapor phase corrosion. Very slightBorax-Glycol, Light yellow stain in liquid sedimentCondensate, phase. No pitting.1/2% NACAP,pH 10.5

23A 2-1/4% 66-2/3 Very slight vapor phase corrosion SlightBorax-Glycol, pitting in liquid phase sedimentCondensate,1/2% NACAP,pH 10.5

9

TABLE I I

Results of 10 Year Inspection Aluminum Panels

Photo Inhibitor Dilution, SolutionNo. Combination % water Results Appearance

24 2-1/4% 3 Heavy vapor phase corrosion. ModerateBorax, Moderate-heavy corrosion in white1/4% MBT, liquid phase. sedimentpH 10.5

25 2-1/4% 3 Moderate vapor phase corrosion. Very slightBorax-Glycol, Moderate corrosion in liquid sedimentCondensate, phase.1/4% MBT,pH 10.5

26 2-1/4% 3 Moderate vapor phase corrosion. Moderate-Borax, Light stain in liquid phase. Light yellow1/2% NACAP, sedimentpH 6.00

27 2-1/4% 3 Moderate vapor phase corrosion. ModerateBorax, Slight-moderate coating in liquid sediment1/2% NACAP, phasepH 10.5

28 2-1/4% 3 Moderate vapor phase corrosion. SlightBorax-Glycol, Heavy coating in liquid phase. sedimentCondensate,1/2% NACAP,pH 10.5

29 2-1/4% 66-2/3 Moderate-heavy vapor phase cor- ModerateBorax, roslon. Moderate-heavy coating white1/4% MBT, in liquid phase. sedimentpH 7.72

30 2-1/4% 66-2/3 Moderate vapor phase corrosion. Slight-Borax, Heavy coating in liquid phase. moderate1/4% MBT, whitepH 10.5 sediment

31 2-1/4% 66-2/3 Moderate vapor phase corrosion. SlightBorax-Glycol Heavy liquid phase corrosion, sedimentCondensate,1/4% MBT,pH 10.5

10

TABLE II - (Continued)

Photo Inhibitor Dilution, SolutionNo. Combination % water Results Appearance

32 2-1/4% 66-2/3 Very slight vapor phase corrosion. Moderate-Borax, Slight-moderate stain and pitting heavy white1/2% NACAP, in lia'jid phase. sedimentpH 7.88

33 2-1/4% 66-2/? Moderate vapor phase corrosion. Slight-Borax, Light scattered pitting and stain moderate1/2% NACAP, in liquid phase. sedimentpH 10.5

34 2-1/4% 66-2/3 Vapor phase okay. Light overall Moderate-Borax-Glycol, coating In liquid phase. light yellowCondensate, sediment1/2% NACAP,pH 7.60

35 2-1/4% 66-2/3 Slight vapor phase corrosion. Very slightBorax-Glycol, Moderate pitting In liquid phase. sedimentCondensate,1/2% NACAP,pH 10.5

1

APPENDIX B

12

TIN COATED SjCEt i 'ELS

irCbCin Undfluted Lut lent: tAi)I with v31 Icu,3 H.hibhci

T IN COATED STLEL A~

JI )f ',/ene GICj i cu.

15 ittt

TIN COATED SICEL t-nhLiLS

:c if 3 - 13*;. £ttylene G~C I 1l, tC 1/3, watct, wiLto vat hk~us irhib~

Ilt M0s4Z S7ELt PANELS

ci.-tt.inrnet t~iL' 3- IP. iy !:t Gly~vlf, :6-2/3% water, wit h vorious nb

a,

Powl.s Inmmrsed In 33-1/n gthylww g1y.Io, 4"-2/3flterp wIt various Inhibitors,

.... .. ....

DOCUMENT CONTROL DATA • R&D(SC Ce ,. C V IAIS itt i-rt, iii . i te ., hody of aha nere and inet ing an oit atton miait h. ntered whep lite o v llt put tI, rie IIteii'tedi)

O'I.INATIN ( ACT\ITY (C rrrnrfrt njafe or) 2.m AF.PORT Srfi!JITY C LAISIFICA lION

U.S. Army Aberdeen Research & Development Center UnclassifiedCoating & Chemical Laboratory 2h GnOup

Aberdeen Proving Ground, Maryland 210053 nEPORT TITLE

STUDY OF LONG TERM PACKAGING OF ETHYLENE GLYCOL ANTIFREEZE

4 DESCRIPTIVE NO'ES (Type of report and inciteaeve dalete)

Final Report5 AUTHOR(S) (Last name., first name. initial)

Conley, James H.

6 REPORT DATE 74. TOTAL NO. OF PAG6S 7b. NO. Or REFI

July 1969 24 6Ba CONTRACT OR GRANT NO. 98. ORIGINATOR'S REPORT NUMBER(S)

AMCMS Code No. 5025.11.803 CCL #268b PROJECT NO

G062105A109 Ob. OTHER REPORT NO(S) (Any oternumbers thatmay be as.ai*idthise report)

10 AVA IL ABILITY.'LIMITATION NOTICES

This document has been approved for public release and sale; its distribution isunlimited. Qualified requesters may obtain copies of this report from DefenseDocumentation Center.

11 SUPPLEMENTARY NOTES 12. SPONSORING MILITARY ACTIVITY

U.S. Army Materiel CommandWashington, D. C. 20315

13 ABSTRACT

The object of this study was to investigate conditions which would effect longterm packaging of ethylene glycol antifreeze. Factors investigated were pH,dilution, different inhibitor systems and different metals.

Aluminum and tin-coated steel panels were partially immersed in ethylene glycolsolutions contained in test jars at room temperatures for a period of ten years.Inhibitors used in this study included borax, borax-glycol condensate,mercaptobenzothiazole, and the sodium salt of mercaptobenzothlazole. pH valuesranging from 6 to 10.6 were used. Test solutions contained 0%, 3% and 66-2/3%water.

No system was adequate for 10 years storage. All systems exhibited corrosion inthe liquid phase and/or the vapor phase.

DD oJAN64 1473 UNCLASSI FIED2 1 Security Classification

1 -40 A Pe,. ii ,

ntifreeze PackagingInhibited Ethylene GlycolCorrosionMercaptobenzothi azoleBorax-Glycol Condensate

INSTRJCTION S

I. ORIGINATING ACTIVITY: Enter the name and address 10. AVA LAfllLITY/LIMITATION NOTICES: Enter any lim-of the contractor, subcontractor, grantee. Department of De- itations on further dissemiration of the report, other than thousefense activity or other organization (corporate author) issuing imposed 1)y security classifcation, using standard statementsthe report. such as:

2a. REPORT SECUITY CLASSIFICATION: Enter the over- (1) "Qualified requesters may obtain copies of thisall security classification of the report. Indicate whether eport from DDC""Restricted Data" is included. Marking is to be in accord-ance with appropriate security regulations. (2) "Foreign announcement and dissemination of this

2h. GROUP: Automatic downgrading is srtecified in DoD Di- report by DDC s not authorized."rective 5200. 10 and Armed Forces Industrial Manual. Enter (3) "U. S. Government agencies may obtain copies of

the group number. Also, when applicable, show that optional this report directly from DDC. Other qualified DDC

markings have been used for Group 3 and Group 4 as author- users shall requeMt throughized.

3. REPORT TITLE: Enter the complete report title in all (4) "U. S. military agencies may obtain copies cf thi%capital letters. Titles in all cases should be unclassified.If a meaningful title cannot be selected without classifica- report directly from DDC Other qualified users

tion. show title classification in all capitals in parenthesis .immediately following the title.

4. DESCRIPTIVE NOTES: If appropriate, enter the type of (5) "All distribution of this report is controlled. Qual-

report, e.g., interim, progress, summary, annual, or final. ified DDC users shall request throughGive the inclusive dates when a specific reporting period iscovered.

If the report has been furnished to the Office of Technical5. AUTHOR(S): Enter the name(s) of author(s) as shown on Services, Department of Commerce. for sale to the public, indi-or in the report. Enter last name, first name, middle initial. cate this fact and enter the price, if known.If mil'itary, show rank and branch of service. The name ofthe principal author is an absolute minimum requirement. 11. SUPPLEMENTARY NOTES: Use for additional explana-

6. REPORT DATE Enter the date of the report as day, tory notes.

month, year, or month. year. If more than one date appears 12. SPONSORING MILITARY ACTIVITY: Enter the name of

on the report, use date of publication, the departmental project office or laboratory sponsoring (pay-,ingl for) the research and development. Include address.

7a. TOTAL NUMBER OF PAGES: The total page countshould follow normal pagination procedures. i.e., enter the I.. AISTRACT: Enter an abstract giving a brief and factual

number of pages containing information. tummary of the document indicative of the report, even thoughit may also appear elsewhere in the body of the technical re-

7b. NUMBER OF REFERENCES Enter the total number of port. If additional space is required, a continuation sheetreferences cited in the report. shall be attached.

8a. CONTRACT OR GRANT NUMBER: If appropriate, enter It is highly desirable that the abstract of classified re-the applicable number of the contract or grant under which ports he unclassified. Each paragraph of the abstract shallthe report was written, end with an indication of the military security classification

8b, 8c, & 8d. PROJECT NUMBER: Enter the appropriate of the information in the paragraph, represented as (TS), (S).

military department identification, such as project number, (C), or (U).

subproject number, system numbers, task number, etc. There is no limitation on !he length of the abstract. How-

9a. ORIGINATOR'S REPORT NUMBER(S): Enter the offi- ever. the suggested length is from 150 to 225 words.

cial report number by which the document will be identified 14. KEY WORDS: Key words are technleall) meaningful termsand controlled by the originating activity. This number must or short phrases that characterize a report and may be used asbe unique to this report. index entries for cataloging the report. Key words must be

9b. OTHER REPORT NUMBER(S): If the report has been selecte$ so that no security classification Is required. Iden-

assigned any other report numbers (either by the originator fiers. such as equipment model designation, trade name. mili-

or by the sponsor), also enter this number(s). tary project code name. geographic location, may be used askey words hut will he followed by an indication of technicalcontext. The assignment of links, rules, and weights isoptional.

UNCLASS I FIEDSecurity Classification