NBSIR 76-1074

Operation Manual for

30,000 Ibf Constant- Load

Testing Machine

D. E. Marlowe and W. H. Appleton

Engineering Mechanics Section

Mechanics Division

Institute for Basic Standards

National Bureau of Standards

Washington, D. C. 20234

October 1976

Prepared for NASA Langley Research Center

Hampton, Virginia

NBSIR 76-1074

OPERATION MANUAL FOR

30,000 Ibf CONSTANT-LOAD

TESTING MACHINE

D. E. Marlowe and W. H. Appleton

Engineering Mechanics Section

Mechanics Division

Institute for Basic Standards

National Bureau of Standards

Washington, D. C. 20234

October 1 976

Prepared for NASA Langley Research Center

Hampton, Virginia

U.S. DEPARTMENT OF COMMERCE, Elliot L Richardson, Secretary

Edward O. Vetter, Under Secretary

Dr. Betsy Ancker-Johnson, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Acting Director

TABLE OF CONTENTS

Page

1. SCOPE 1

2. GENERAL DESCRIPTION 1

2.1 Force Measurement and Control System 1 2.2 Force Actuator 5 2.3 The Loading Frame 5

3. THEORY OF OPERATION 5

4. OPERATIONAL CONTROLS AND INDICATORS 6

4.1 Force Measurement and Control Control System 6

4.2 Motor Controller 10

4.3 Portable Load Indicator 10

5. OPERATION 23

5.1 Establishing the Operating Temperature 23

5.2 Applying the Force Level 23

5.3 Constant Load Operation 25

5.4 Changing the Amplifier Gain 25

5.5 General Notes 26

OPERATION MANUAL FOR

30,000 Ibf CONSTANT-LOAD TESTING MACHINE

Donald E. Marlowe

ABSTRACT

A 30,000 Ibf (133 kN) constant-load testing machine has been designed, and ten of these machines have

been delivered to the NASA Langley Research Center.

Each machine is equipped with a self-contained, closed

loop load controller which is maintained at a constant

temperature, independent of the external ambient con- ditions.

Key Words: Creep; instrumentation; stress rupture;

testing machine.

1. SCOPE

This manual presents the information necessary for the operation

and maintenance of the 30,000 Ibf (133 kN) constant- load testing machines

(CLTM) . Included are a general description of the machine, a description

of the detailed operation of the machine components, and several associated schematics and tables.

2. GENERAL DESCRIPTION

The CLTM, shown in Figure 1, consists of three major subassemblies:

a force measurement and control system, a force actuator, and a loading

frame. A brief explanation of the function of each subassembly and its

contribution to the overall system operation will be given here. Specific

details of the operation of each will be found in its respective section

later in this manual. Ten CLTM machines, shown in Figure 2, have been

installed as a test system.

2.1 Force Measurement and Control System

The force measurement and control system includes a dual bridge

load cell force transducer, a closed loop load controller to monitor and

maintain load on the specimen, and a heater and temperature controller

which maintains the transducer and controller at a constant temperature.

This system is housed within the Instrumentation Module. A block diagram

of the system is shown in Figure 3.

1
2
I

Figure 2 - Ten constant load testing machines - The CLTM's are numbered

1 through 10 from right to left.

3
>

•o

UJ ou 2 2 z

COa

(U

4-1 CO

COouucoo

0)3u

CO

(Ua6

4-1 T3C

CO

CUO

>-l oOe

CTJ

l-l 60

CO •HX)

,^Oo

PQ

en

CUM3

bO

•rH ozQ<Q <

////////// 4
One bridge of the dual bridge load cell is used to measure the load

applied to the specimen. This load is indicated on the Portable Force

Indicator provided with these machines. The output from the second

bridge of the transducer is monitored in the load controller. The

difference in the signals between the measured load and a preset load is

displayed on the Null Meter in the Instrumentation Module. The machine

acts to reduce the load error to within the preset deadband of the

controller

To provide the load cell and amplifier with a constant environment

which is independent of the ambient conditions, a heater and temperature

controller are contained within the Instrumentation Module. Heat is

provided by three strip heaters distributed around the load cell. The

temperature of the Instrumentation Module is maintained at about 50 °C

(120 "F) . This is achieved by supplying direct current power to the

heater in varying amounts matching the heat energy loss of the Instrumentation Module. The Load Control-Temperature Control package is fixed

to the load cell. Power supplied to the heaters varies from zero to

approximately 250 watts as needed to maintain temperature.

2.2 Force Actuator

The force actuator in this machine is a screw jack driven by a 0.25

hp (190 W) reversible electric motor through a 3000:1 double-reduction

worm gear. The total stroke for this system is 18 in (46 cm).

Initial specimen loading may be accomplished by manual operation of

the actuator or by tightening the retaining nuts on the pull rod of the

loading frame.

2.3 The Loading Frame

The loading frame for the CLTM is designed to resist specimen loads

up to 30,000 Ibf (133 kN) . Each of the ten CLTM systems can operate

independently or any combination of the ten machines can be operated

together, as desired. The loading frame provides mounting support for

the force actuator and the motor controller. The power supply for the

load-control system is mounted on CLTM 6. A system power circuit breaker

is mounted on CLTM 1.

3. THEORY OF OPERATION

A circuit diagram of the CLTM is shown in Figure 4. The load

sensing transducer of the CLTM is a 50,000 Ibf (220 kN) capacity load

cell. The cell is instrumented with two similar strain gage bridges

having a nominal rated output of 2 millivolts per volt (2mV/V)

5
The output of the secondary bridge (Bridge B) of the load cell is

used to measure the load applied to the specimen. This measurement is

made with the Portable Force Indicator provided with these machines.

After the desired force has been applied to the specimen, as indicated

by the secondary load cell bridge, the output of the primary bridge

(Bridge A) is balanced against the output of the load controller. The

difference between these signals is displayed on the Null Meter of the

Instrumentation Module. Any change in load then appears on the meter as

a deviation from the meter zero point. Meter deflection of a fixed

amount, i.e., a load change of a fixed amount, causes operation of one

of two optical switches. These control the motor circuit and the motor

operates so as to reduce the error to within the desired limits. The

bandwidth of allowed load change, which will not cause the motor to

operate, is adjustable by changing the gain of the closed loop load

controller.

Although the load cell is temperature compensated and a change in

temperature will not significantly change its output, the amplifier of

the closed loop controller must be maintained within somewhat tighter

temperature limits. The temperature of the load cell and amplifier is

maintained at approximately 50°C. To provide a heat stabalizing mass

for the amplifier, it is clamped directly to the case of the load cell.

Heat is supplied to the system through three strip heaters, each rated

at 250 watts at 240 V, which are also clamped to the load cell.

The temperature is sensed by a thermistor Tc (Fig. 4) mounted in

close proximity to the amplifier in the Instrumentation Module. A voltage divider formed by thermistor Tc and a variable resistor determine

the current applied to the base of the power transistor in series with

the heaters. This circuit supplies direct current power to the heater

from zero to 150V, as needed to balance the heat loss of the Instrumentation Module. A second calibrated thermistor Tm is provided from

which it is possible to monitor the temperature of the amplifiertemperature control package. This is accomplished by measuring the

voltage between pins D and G of the connector on the outside of the

Instrumentation Module. The resulting voltage equals the voltage drop across the monitor thermistor whose resistance changes with temperature.

4. OPERATIONAL CONTROLS AND INDICATORS

Operational controls and indicators for monitoring the operational

status of the creep machine are listed below along with a description of

their respective functions. ,^

4.1 Force Measurement and Control System

The controls for this system are located on the end of the Instrumentation Module (Fig. 5). They are as follows:

6
SZ2-03V301G SW
Figure 5 - Control panel of instrumentation

module

j 8
Null Meter . Located behind the weather tight cover on the left

side of the panel, this is a multiple purpose micro-meter which, in

conjunction with the position of the mode-selector switch, indicates the

amplifier unbalance or the error from the set point.

Pilot Light . Visible in the null meter, this light indicates the

flow of current to the heater circuit.

Balance-Operate-Gain Mode-Selector Switch . Located behind the

weather tight cover at the top of the panel, this switch performs three

functions:

1) Switch up-BALANCE. The amplifier input is shorted allowing the

amplifier to be balanced: A light is lit for meter observation.

2) Switch center - OPERATE: The normal operating mode. The

pilot pilot light shows heater operation.

3) Switch down - ADJUST: The system operates in a normal mode

while the gain of the load control amplifier is set. A light

is lit for null meter observation.

Gain . This potentiometer is used to adjust the gain of the closed

loop force controller. This gain adjustment sets the width of the

deadband of the motor controller, i.e., the load range about the load

set point within which the load-maintainer will not operate.

Temperature . This potentiometer is used to adjust the temperature

set-point of the controlled environment inside the Instrumentation

Module. Clockwise rotation of the potentiometer increases the temperature. The pilot light visible on the null meter begins to glow when

power is supplied to the strip heaters.

Load Cell Zero . The Load Cell Zero Potentiometer is used to balance

the primary bridge of the force measurement circuit. After the desired

load is applied to the specimen, the potentiometer is adjusted until the

primary load cell circuit output is zero as indicated on the Null Meter.

AMP Balance . With the input to the amplifier shorted, this potentiometer is adjusted until the output of the amplifier is zero as indicated by the Null Meter.

Internal Function Connector . A connector is provided through which

it is possible to monitor several of the internal systems of the Instrumentation Module. Those internal functions which may be monitored are

as follows:

9
Pins Functions

A and B The electrical signal of the primary load

cell bridge circuit.

C and G Differential amplifier output signal.

D and G Temperature.

E and F Secondary load cell bridge output signal.

I and J Secondary load cell bridge input voltage.

Pins E, F, I and J of this connector are in use when the Portable

Load Indicator is employed to read the load applied to the specimen.

The controls for this system are located on the starter box on the

column of the CLTM. The controls for this system are as follows (Fig.

ON-OFF . Applies 460 v, 3 phase operating power to the motor circuits

housed inside the starter box.

HAND - OFF - AUTOMATIC . Selects the manual or automatic loadcontrol mode for machine operation.

FORWARD - OFF - REVERSE . With the machine in manual mode, selects

the direction of actuator travel.

RESET . Provides circuit breaker protection to the motor controller.

This instrument is used to read the load applied to the load cell.

These measurements are made on the secondary bridge of the load cell.

The controls for this instrument are described in the instruction manual

for the instrument. However, as they relate to these creep machines,

the controls function as follows (Fig. 7):

SPAN . The span setting for each load cell is 1.34 as shown in

Balance . This adjustment provides initial bridge zero. The balance

setting for zero bridge output under each test condition should be

recorded at the beginning of each test.

Measure . This is the readout control for the instrument. It

should be used in conjunction with the Null-Balance-Meter on the indicator to establish the force applied to the specimen.

4.2 Motor Controller

6):

4.3 Portable Load Indicator

Table 1.

10
11
Control panel of portable load

indicator

12
iNATTOI^iAL

i Tahle_L -

PlJi' CLTM

firi) 0^^ STA'IPARDS F'^i^cF

1 ALT'^PATtON PAGE 14

VT«^HAY ir CALlUf^ATED TO 3rc^n i .r.F TEr^5iO" APRIL 16» 1976

CALI-PrtTIO'' IM aCC^^P^.' r . ri w 1 ' L. TErJSlOrj PAT^ FOR 23 OEGREES r APPLIED

1 OAD

DEFL^^CTIOf'S OI'SERv/ED

nURlMO CLIRPATIOM

DEVIATION!

FT TTrn

S FPO"

f^i ip\yp

VALUES

CD AfJi r K ' r': CHAMGE

h r (J M

IN LBF

i- RU'! 1 RUN 2 RUN 1 FITTEP

V 1 r\ V C

PREVTOiJS

rAi TPDATTOM

OV'j'J • — H _— r)

I () . 4000.

n n 0

\j \J 'J \J • 12 '.2. 18^6.

1206.

I8a«.

-5.

c . -1 . ^

1207.

1J flnti e u H

eooG.

J

1 n nU nU n'J . 24 U.

:30'^n. 2406.

3005.

1.

c • 6. 2400.

12000.

14000.

36i'6.

42f'n.

3604.

4195.

9.

^

7. 3597.

' 16000.

18000.

47Q7.

53Q1.

4800.

'=;3Q0.

1. 4.

_7 . .4796.

20000.

22000.

59^-?.

65Q'i.

599?.

659P.

-7.

-7.

-7.

-3.

5999.

no 1 J i . 24000.

26000.

7198.

781

7204.

7812.

-6.

1.

-0.

3.

7204.

28000.

30000.

8417.

9023.

8415.

Qn22.

3.

4.

1.

3.

8414.

9019.

STAr.'D ''"^OIZEP RE '^r iNlG = 1.34

NOTE - INITIAL ^'BS CALIPPATION > NO PRE^'TOUS DATA AVAILABLE fqp COMPARISON.

THE FOLLO-.'ING C "-LI'^PATION EOiJ/*TIO^i» •^ESCRTBE'^ IN '=^FCT'''0'" 7.2 OF ASTM MjrTMop - E 74-7u» WAS FITTED TO TH*^ CALIR^^^TI^N CATA THF vethoq pp LEAST SQUARES.

DEFLE^TTQfl - (A) + (rDCLOA*") + (OCLOAi^ SQU'PEO)

WHE"F i r .1 7616UP?

B = .2970'=^l + no

C - .1CC093-06

UNCERTAINTY = 41.00 L'^F

TENSION LO'.n T'^ll F Fop r>^ r^rppcre; f

DEFLECTION LOAD INTERPOLATION "^A^iLES

UNITS LPF UNITS L^JF UNITS L«F

lonn. 3303. too. 333. 10. 33.

2000. 6659. 200. 665. 20. 67.

3000. 10006. 300. 9P^. 30. 100.

4000. 13346. 400. 1330. 40. 133.

5000. 16679. 500. 1663. 50. 166.

6C00. 20004. 600. 19Q5. 60. 200.

7000. 23322. 700. 23.^0. 70. 233.

8000. 26633. POO. 2660. 80. 266.

9000. 29937, OOO. 2993. 90. 299.

10000. 33233.
NATTOiJAL pii"EAl] OF ST^'IOAF^OS Ff'^CF CALTHRaTTOM P^G^ \2

TnhTe 1 - CLTM 2 tramsducffs LC*"^ f^LL ""^

, 5000^-0 VTSHAY IfOIC^TOR MRS 1 «6R3f.

calibk;tfo TO .ICOno LfiF TEMSIOM APRIL l'^» 1^76

CALIt^'OATlOr' IN ACCnRDA"CE WITH1 AST'i ^•FTHO^ E 74-74

TEMSION OATA FOF 23 0EG9FES r

APPLIED

LOAD

DEFLCTTIO'lS Or;SF.RVFD PEVlATTnNS FRn-'

OURT'-iO CALim^ATI^^' FITTFO riipvE

VALUES

P"ROM

CHAMGE

FROM

IN LBF

PU ' 1 RUN ? RUN 1 PUN ? FITTED

CURVE

Pde;vtoi )c; CALIBRATION

3000. 897. 89U. -5. -P. °02.

'+C00.

6000.

11^7.

1803.

1197.

1804.

-3.

5.

-3.

6.

1200.

1798. aoco.

10000.

23<^7.

3C •4.

239?.

3001 . 1.10.

-4.

7.

2396.

2994.

12000.

mooo.

36^2.

411?.

3602.

4196.

8.

-2.

8.

2.

3594.

'il94.

1600C.

18000.

47Q4 , "^3^1 . 4795.

5395.

-1.

-6.

-0.

-2.

4795.

'5397.

20000.

22000. 6599.

5993.

6596.

-9.

-4.

-6.

-7.

5999.

6603.

24000.

26000.

7201.

78? n. 7204.7822.

-6.

8.

-3.

10.

7207.

7812.

28000.

30000.

8415. 84ia.

"028.

-3.

1.

1.

4.

8418.

9024.

STAf.'DARniZE^

MOTE - IMITIAL -^'BS CALIP

PEANIr'G = 1.34

RATTOiNif ^|0 PREV'TOUS DATA A\"^TLA'^LF FOR cofypARisorsi.

THE FOLLOWirJG C '<LT'- RATION FOMATIOflr PFSC^TRE^ P' "^^FCT^C'I 1,2 OF A'^TM methhi

F 74-7Up •.'AS FITTrn TO Tl-F C ri.I P'' AT I OM DATA T^r ME"''H'^n OF LEAST SOi.'Af^FS.

DEFLECTTOrJ = (A) + (B)(l-OAn) + (C) (LOAP SQU'^RE 0)

WHERE A = .RtinO'^3 + 01

B = ,207610+00

C = .«571540-07

UNCERTAL-ITY = 48.00 l."F

TEMSIOM LO'^ TAHLE FOR 23 ^FGPF^s C

DEFLECTION LOAD INTERPOLflT ^ON TAPLF5

UNITS LBF UNITS L"F UNITS LP^F

lopn. 33?'^. inn. 3^0. in« ^3.

2000.

3000.

6677. ?00.

10019. 300.

6*^4.

996.

2n.

30.

66.

100.

4000.

5C00.

13354. 400.

16681. =;oc. 1328.1660.

40.

50.

133.

166.

6000.

7000.

20002. 600.

23315. 700.

19Q2.

23^4 . 60

70.

19Q.

23?.

8*^ ?0.

9C00.

26621. 800.

299;>0. 900.

26^6.

2988.

80.

90.

266.

290.

lOCOO. 33213.

14
, N/\TTO-iAL

Table 1 - CLTM 3

1

' AKU r> r ( Lt CALTPRATTON PAGr in

r

i TR/\riSL)i iCFfvS LOA^ "^LL 0. s^oor^-R V/T«^MAY It DTCATOR ^'RS 1 ^6036

I A 1 T r->Q " T 1 I- AL 1 DrX ^. 1 r.O TO 3C0^n L6F TPMC T ^^ 1 APR XL 24 » 1 976

i CALI'^RATIO " If) ACC^RHA MCE •'ITH ASTM ^:FTHO^ E 74-7U

TEflSIOil "^ATA r u*' 23 OEGr^FES C

A DDI T t^n LOAD

DEFL'-TCTIO'I'^ Or:^ER\/^_D

DIJRT 1^ CALinRATinn

PEVIATIONF FRO""

FITTED Cl'RVE

\/ A 1 1 ICC f^ROM

! H " r-lGE

T M 1 ^ P PU ' 1 RUN 2 RUM t RUN

_ cr T TTCn

CURVE CALI^^^ATTON

3000. 890. -It -6. 896.

/I n 1^ A 4 0 u U . 6000.

ll'^'^. 1189.

1792.

-6.

4.

-5.

3.

1 194

1789.

Q n fi n o U J L' • looon.

23^1. 238C).

2^84.

5.

6.

3.

2.

2386 • 2982.

1 ^ U u u . 14000.

3590.

417T.

3532.

41.78.

11.

2.

3.

1.

ObTS . 4177.

X1 Ar> n n 0 u u u • 18000. 537n.

4777.

537t . 4.

-5.

1.

-4.

4 77o •

' 5375.

20000.

22000.

5967.

657P.

5966.

6566.

-8.

-3.

-9.

-9.

0975 • 6575.

24000.

?600n.

7178.

77a 1.

7175.

7776.

2.

3.

-1.

-2.

' 1 ro t 7778.

28000.

30000.

83=3.

8984.

8381 . 8986.

3.

2.

1.

4.

8380.

8982.

STAfO-PniZER REAOI^lG = 1.34

NOTE - INITIAL 'IP'^ CALI^RATTONrNOPREVTOUS DATA AVAILABLE FOR COMPARIS'^M.

THE FOLLO'.'irjG C^LIf'RATTON EQ'JATinM, rESCPTBE^ Ifl '^rCT"'ON 7,2 OF ASTm "'E'''H0D E 74-74 » ..'AS FITTFP TO THE CALIP^ATlnri RATA "Y TH^ mfthoo oF LEA?T SQUARES.

DEFLErriON = (A) 4- (p)(LOAn) (C)(I.OAP SOU^RFQ)

l-'HE^F A = .48*^3454-01

R = .296<^74 + 00

C = .75QP28-07

UflCERTAlNTY r 40.00 LPF

TENSION LOAH T^HLE Fpp P3 opQprrc; c DEFLECTlorj LOAD TNTERPOLATTqn TAPLES

U^!TTS LRF UNITS L^F UNI^S LPF

lono. 3348. mo. 3^4. 10. 33.

2^00. 6707. 200. 667. 20. 67.

3^00. 10060. 300. 1001. 30. 100.

4000. 13407. 400. 1334. 40. 133.

5000. 16748. 500. . 1668. 50. • 167.

6000. 20034. 600. 2002. 60. 200.

70-^0. 23415. 700. 233S. 70. 234.

80 TO. 26739. 800. 266°. 80. 267.

9900. 30058. 000. 3002. 90. 300.

10000. 33372.

15
- rjATIUMAL MirrAti C «;T/\fiOARDS Fr.rQf_ CALT"P;TTOri

ToKlo 1 r.T.TM 4 PAGP" 6

TRr';sniicrr<s 106Q36

CALIbRATEP TO 300nn l^^"^ TFMSIOn APPTL 14,1 Q75

CALl3P'\Tl0f' IM rCCPoPAMCE WITH AST" P-'FthcH E 74-74

TEMSTON FO^ ?7> ""jEG^EES r

APPLIED

LOAD

defl::ctioiis

DliRTNiG C'\L

OFSEPVFD OFVlATTOriS F^O"^

IBRATlOri FITTFO CMRvyF

VALUES

FROM

CHANGE

IM LbF

PU'l 1 PUM P RDM 1 oiirj o ^ITTEn

CURVE

PQFV^ynuS

CflLI'^RATToM

30nn. ono. -s. -u. POU.

f>OCO.

12i 0.

18'^n.

120C. -2. -2.

1"01. 2. 3.

1202.

1798.

80CO.

10000.

2393.

2997.

2393. -2. -2.

?Qqq, 6,

2395.

2993.

12000.

ItiOnn.

36^0.

UIP.Q.

3600. 8. 8.

U191 . -3. -1.

3592.

41Q2.

160C0.

18000.

t+793.

53^1 . M79«. -0. 5.

5397,. -t|. -2.

4793.

5395.

20000.

2200C.

59^3.

65Q7.

5^95. -6. -ti.

6598. -6. -5.

5999.

6603.

2t+000.

26000.

72?'+.

782'-^. 7206. -t^. -2.

78in. 5. 3.

7208.

7815.

28000.

30000. 90^1.

8424. 3. 2.

9032. 0. 1.

P422.

9031.

STAMDAoniZE^

r:oTE - rjiTiAL mrs cali^<

RE^^^JO = 1.34

PATTOiJ* NO PRE^'IOUS DATA AVAILABLE F0° COMPARISON.

THE FOLLO WING C U.T"-=?ATtom EO'.KTIO'U ^rccRiBEH I^! <=:FCTTo^' 7.? OF fi«;TM "E'^mO

E 7h-7U» •:AS FITTrD TO TIF C -^L I PR T I nCTA THt^ t^^F'^hOPj OF LEAST S'^"A^FS,

DEFLECT lOM = (A) + (R)(I.OAi~) + (C)(LOAn SOII'^REO)

WHFPF ^ - . 1 2f=«7'S6+'^? 8 = .2nf.7ll + 0n

C = ,129528-06

UMCFRTAI;iTY = 3^.00 LPF

TEMSIO^l LCn Tahlf >="op ?3 npnPF'-c; c DEFLECTION LOAD IMTERPOLATTOM TABLES

UNITS LBF UNITS LHF UNITS L^F

looo. 3323. 100. 332. 10. 33.

2000.

3000.

6679. 200. 663. 20.

10024. 300. 9°5. 30.

66.

100,

ttOOO.

5cno.

13361. 400. 13'>7. 40.

16687, 500. 165Q. 50.

133,

166,

6000.

7000.

20G04. 600. 19^0. 60.

23312. -700. 23P2. 70.

19Q.

232.

80O0. 26611. aOO, 2654. 80. 265.

900 (K 2Qf^0 0 . 900. 2985. 90. 299.

10000. 33180.

16
MATIOriAL HMREAU 0~ '",TA mARDS FOPCF

Table 1 - CLTM 5 CALinPATTON PAGE 16

TRAMSDIICFt^ S LO'\n '•'"LI. rio. Sfi0fi'--p VT<^HAY P'OTCATOP 1 A6f^36

CALIbKATED TO jOO'^n L:^.F TEr.SIOM APRIL 22f 1976

CALI^P'VTIOri T^l ACCORD'' "CF WITH AST^' f'FTMOn E 74-74

TENSIO'I PATfi FOP 23 OEGOFFS C

APPLIED

LOAD

DEFLrcTIOMS Or^fTRxjfi^

OURT'IG C'XLT'^RATIor!

DEVIATIoriS FRO"

FITTED ("iiRVF

VALUES

FROM

OH'^^!GE

FPOM

IN LBF

RUv 1 PUN ? RUN ] RUN 2

FITTED

CURVE

PREVIOUS

CALI'^RATTONi

300 n. -5. -6. 901.

4000 . 6000.

11^7. 1190.

1794. 179P.

-0. -7.

3. 7.

1197.

1791.

8000.

10000.

23R5. 2367.

29-^1 . 2992.

-0. 2.

-0. 11.

2385,

2981.

12000.

14000.

35??. 35301.

^^175. 41«':'. 4. 10.

-2. 3.

3578.

4177.

16000.

IflOOO.

47^4. 477°.

5374. 5366.

8. 2.

-3. -11.

.4776,

5377.

20000.

22000.

5972, 5967.

657-!, 6581.

-6. -11.

-11. -0.

5978.

6581.

24000.

26000.

71R6. 7183.

77^1^. 7796.

0. -3.

5. 5.

7186.

7791.

28000.

30000.

8397. 8399.

QOnn. 9007.

-0. 2.

3. 2.

8397.

9005.

STAND.''RniZE^ READTlG =

K'OTF - ir'ITlAL fflS CALTPPATTON, NO

1 .34

PREVIOUS DATA AWflTLA'^LF FOP C0MP'\PI5nN.

THE FOLLOWING C iLinR '\T lOf i TQit/'TTOMf rrccPTREn If,' ';FCTTo^' 7

E 74-74» WAS f^I"^Tcrn TO TH"^ C^LIRP^TIOM PATA TH^^ MF'^HOn

.? or PSTM r^FTMOn

OF LEAST SOUARES.

DEFLECTIOM = (A) + (pjCLOA"") + (Od.OAH SOIJ/'RED)

WHERE A = . 1?R7(S2 + '^^ P -

C - .?o^^260 + 0n

. 14RPR2-06

UNCERTAI^;TY - 4n.00 \Sf

TEtlSIOM LOAH TA^LE Fqp ?3 npGRF'^5 0

DEFLECTIorJ LOAD INTERPOLATION TAhlES

UNITS LBF UNITS LHF UNITS LPF

33.14. 1 on. 3^3. in.

2000. 6704. 200. 665. 20. 67.

3000. 1CC63. 300. 903, 30. 100,

4000. 13410. 400. 1330. 40. 133,

5000. 16746. 500. 1663. 50. 166,

6000. 20072. 600. 1995. 60. 200..

700c. 233.q6. 700. 23''P. 7n. 233.

8OOO. 266Q0. ftOO. 2660. 80. 266.

90nO. 29"'^3. 900. 3995, 90. 299.

10000. 33266.
N'ATTOiML FliiPEAU OF STA IOARDS FOr^CF

Table 1 - CLTM 6 rALTRP'^TTON

TRAi iSDiirFRc; LO/ n '"•^LL NO . 59007-R vtc;hay piniCATOP fR?; lf^6.'^"^6 CALIbKATED TO 30000 LRF TEriSIO'l APR IL

CAI_I^PATIO^I in ACCORHA MCE WITH AST^" MFTHOn E 74-74

TFrJSIOU PATA

APPLIEP DEFL'^CTTOilS O'-SERVFD

LOAD DURING CALIBRATIOM FITTED C'IRVF

VALUES

FROM FRO'.'

RU-' 1 RUM 2 PUN 1 ?

TT T T T V r\ FTTTEP

CURVE CAl. inpATTOM

3000. 91'^. 90^. -3. -8. 913.

li p. i"' n 1 ? • o 6000. 181'U1 5 0 P. i <i 'J D . 1811.

— T _ c: "J • ~D . 7. 4.

l<; 1 1

1807.

8000. 24'j7.

10000. 3012.

2404.

300".

d» —1

9. 6.

^ #1 C

3003.

12000. 36;'5. , 14000. '12-0.

3607.

4204. -2. 2.

1 £ n o o602 . 4?02.

16000. 48'5.

18000. 54-^2.

4806.

5403. -3. -2.

tt a r\ ~x. =^405.

20000. 6on.

22000. 66''^.

6003.

6605.

-7. -5.

-8. -6.

6008,

661 1

24000. 7213.

26000. 73'P.

720P.

7830.

-2. -6.

8. 10.

7215.

7820.

26000. 8427.

30000. ^0,-^6.

8426.

9033.

1. -0.

3. -0.

8426.

9033.

STAMDi^OIZER

nOTE - irilTTAL r-'B*^ Ct'Ll^

PEADIMG = 7ATT0M» HO

1 .34

PRF^'T0Uc; qATA AV^TLa^LF FOP COMpARTSnn.

THE FOLLO ahG C'LT' R ATIOr: EQUATTO

E 74-74» VAS FITTED TO THF CaliRP

"•^f pt^SCRTBE"^ IfJ ^^FCTTOM 7.2 OF A'^^TV ^'FTMO^

ATTOM RATA RY THf- ^T^HRD OF LEA<^T SQUARES.

deflectiom = ( A ) + ( R ) (

' OA-^) + (C) CI OAR SOU'REO)

WH'^f'F A -

P =

C = ,2O72^9+n0

. 1051^3-06

UlxiCERTAIMTY = 41.00 L°F

TErJ=;TOri LOr"^ T'ni f FOP rs(rn,ptrrc: r DEFLECTION LOAD INTERPOLATION "^ARLES

Uf!IT5 LBF UNITS L^F UrJiTS LRF

1 mo. 100. 332. 10. 3'.

2000.

3000.

6645.

99A9.

200. 664. 20.

300. 99i=<. 30.

66.

ion.

4000.

SOno.

13325.

16654.

400. 1358. 40.

50O. 1660. 50.

133.

166.

6000.

7nno.

19975.

23288.

600. 1992. 60.

700. 23-''^. 70.

19°.

?3?.

8000.

9000.

10000.

26593.

29_091.

33181

POO. 2657. 80. 266.

QQ O. 29Qq. 90. 29°.
• MATIOIJAI. niJ-^EAD OF STAMO'NPDS F'l^CE

Table 1 - CLTM 7 CALTnPfTTOri PAGE P

\_Q'\r\ '-^1

I rn ^

c; p Q Q q _ q VTSmAY I' DIC^TOP mJ a W 1 V ^'"S 1 imL 1 Ul W 1 CALIBRATED TO 300 30 l;<f TEN5I0" APRIL lo, 1976

CAl.1^7 ATlO'i If! '^.CC'^f nA"CE ".'TTH AST^' P'FTHOn F 74-7U

TENSIO'J HATA FO^ 23 OEGPEES r APPLIEO

LOAD

DEFL'^CTIO'IS Or-Sr?VFD

ni lRT'l^ CAL. inRMlOII

DEVlATIori'^ FRO'*

FITTED CilFVF

VALUES

FROM

CHANGE

poo*'"

IM Lt3F

PU' 1 PUM ?. RUN 1 "LIM ' FITTEr

CURVE

PPE"IOUS

CALIt^RATTON

3000

P03. -5. -6. 909.

4000.

60C0

12 :6.

le ;.Q. 1203.

1800.

-2.

4.

-5.

3.

1208.

1 805.

8000.

10000

3011 . 2403.

300n.

1.

9.

-0.

7.

2403.

3002.

12000.

luooo

3610.

U2 -U.

3608.

4?00 . 9.

2.

7.

-2.

3601.

fi902.

16000.

18000

,

48:7.

54

4804.

S395.

4.

-2.

1.

-10.

- 4803.

5405.

20000.

22000.

59^6.

66 5.

5996.

6607.

-11.

-5.

-11.

-3.

6007.

6610.

21000.

26000.

7213.

78^6.

72ir^.

782'i.

-1.

7.

-4.

5.

7214.

7819.

28000.

30000.

8431.

Q03n.

8424.

9032.

7.

-0.

-0.

2.

8424.

9030.

STAND'l^IZE^'

MOTE - INITIAL "IBS CALI"

RE/^OIff. = RATIOM. NO

1.34

PRE*'IOli«; DATA AVAILABLE FOR COMPARISOM.

THE FOLLO -.'IMG C ALI^'^MTIOri FQhatTO

E y^-Tt+r -JAS FITTED TO THE C;^LIn7

"t '^trgf^PTHED IM ^ECTTQ^^ 7,?_ OF AST

'-TIr^^i DATA "^Y THr 'lE'HOD Or LEAST

v. "ETHOD

SQUARES.

DEFLETTinri = (A) + (1)

(

_0A'^) + (C) (LOA-^ SQUARE n)

F A r . 1 5?0?0+o?

B =

C = .2P7750+00.920116-07

UNC ERTAIfJTY - 46.00 1 rf

TE^JSIOM LO".^ T^PLE FOP "33 nFGPF<^S C

DEFLEi'TION LOAD INTER°OLATTOrJ ta" LES

UriTTS LBF UNITS L^F UNITS L^F

1000. 3304. TOO. 3-^^?. 10. 33.

2000.

300n.

6652.

9QQ(+.

200. 664.

300. 9^6.

20.

30.

66.

100.

4000.

5000.

13328.

16656.

400. 132«.

=;00. 1660.

40.

50.

133.

166.

6000.

70nc.

19977.

232Q1

600. 19°?.

''OO. 232*=;. 60.

70.

199.

232.

8000.

90no.

26599.

2QP99.

800. 2657.

QQO. 299Q.

80.

90.

266.

299.

10000. 33194.

19
- NATIONAL l-iii^£Ali OF STA^'HARDS FO^CF

Table 1 - CLTM 8 CALTPPATIOri PAGE B

TRAMSOliCFRS LO"^ C^I.L riO. panni-r: VI<^HAY ''TOR

CALIbi^MFD TO 30C?0 LRF TEflSIO'i APR IL 1 5 » 1 976

CALIIPATIO'i IM ACCORD? •"CE WITH ASTM "ETHOn E 74- 74

TEtJSICn OAT A FOi^ 23 OEGPFES r

APPLIFD DEFLFCTTOiiS OPSFHVFD

LOAD nURT^!G CftLinP'\TIOM

DEVIATIOMS FROFITTPn Ci'PVF

^'ALUES

FRO"^'' PHrtNGEFPP"

RU-' 1 RUM ?. RMN 1 r>UM FITTFP

CURVE

PPEVTOU*^

CVLIPOATIOM

3000. 89^. -7. -6. 901

4000. ll'?6. 1196.

6000. 16 n. 179". 3.

-4.

-0.

1200

1798.

8000. 24M. 2400.

10000. 301?. 3004.

3.

14.

2.

6.

2398.

2998.

12000. 36-^7. 3608.

14000. 42'^n. 4200.

8.

-0.

9.

-0.

3599.

"200.

16090. 48"4. 4806.

18000. 53Q^. 5401.

2. -ro.

4,

-4.

- 4802.

5405.

20000. 60j0. 6001.

22000. 66T=>. 660".

-9.

-5.

-8.

-10.

6009.

6614.

24000. 721'=>, 7215.

26000. 78r'c». 7829.

0.

4.

-4.

4.

7219.

7625.

28000. 8433. 8430.

30000. Q04?, 9044.

2.

3.

-1.

5.

8431.

9039,

STAr'D'^rjniZEP READING =

fjOTE - irilTTAL C ALI f^P <\T ION . NO

1 .34

DREVTOUS DATA AVATLA^'LE FOR COMP'\RTSOfl.

THE FOLLO'/IiiG C^LT'^R,^TIOM E'"?',"* T ION' r r.rqcRTBEO IM "^FCT^O" f OF ASTM '."ETmod

E 74-74» -'AS FI"^TFn TO TH^^ CALIRf^AJlOM PftTA nY T^r MF"^HCr) OF LEAST SODAfES.

DEFLECTIOM = (A) + (P){LOA'^) + (OCLOAO fiQiJ^ RED)

WHERE A - .U7Q1 63+^1

B =

C = .298383+00

.^15049-07

UNCFRTAIfJTY = 40.00 LPF

TENSION LOAH TAplE EQP ?3 OEGRFFS C

DEFLECTION LOAD INTERPQLATTQN "^ APLES

UNITS LBF UMTTS L^F UNITS LPF

lono. 3332. 100. 3-^1 . 10. 33.

2000. 6673. 200. 663. 20. 66.

3000. 10007. 300. 904. 30. 99.

4^*00. 13335. 400. 1326. 40. 133.

5000. 16656. •^00. 1657. 50. 166.

6n00. 19970. 600. 198Q. 60. 199.

70O0. 23578. 700. 232M. 70. 23?.

8000. 26578. 800. 2651, 80. 265.

9roo. 2Q873. 900. 29«3, 90. 298.

lonno. 33161. '

20
f

'national f''.)=!EAi.i 0^ STA lOARDS f^^CF.

Tabic 1 ^ijiii y CALT==iPATTOM

TRAMSOUCFPS LOAP i^-I.L. NO. sooOA-R VI'^HAY P'OTCATOR Mf^S 1''6f'36

"CALIBKATED TO 30000 L.3f^ TErJSIO'-' APRIL ?1 »1"76

CALI"'^'"\TIO^' IN AC'"Oop'\

TCnCTn^l HftTft -'CE WITH AST'" MPTMOnCOD \-\cnnccc: r E 74-7ti

APPLIED DE^L^CTIOMS OrSERV^D DEVIATIO^''^ F^^O'" VALUES '"HANGE

LOAD OUR T Mr, CALIBRATION FITT^'D dipVE t^POt^ FPO^^

'IN LctF ------------- FITTED P^E^IOUS

RU I 1 RUM 2 PUN 1 0 CURVE CALIPRATTON

J U 'J u • t+000. 12.- 1208.

—o . -1. -1. 1209.

6000. 131^. 1811, 5. 4. 1807.

flOOO. 2402. 2406. -3. 1. 2405.

10000. 30"^. 3005. 4. 0. 3005.

12000. 36''«^. 3612. 3. 7. 3605.

14000. 42^3. 4?lt. -3. 5. 4206.

16000. 481 n. 4814. 3. 7. -4807.

180C0. 54^4. 'i41n. -6. -0. 5410.

20000. 60:6. 6007. -7. -6. 6013.

22000. 66 1 2. 6613. -6. -5. 6618,

24000. 72?n. 7223. -3. 0. 7223.

26000. 7831 . 1. 3. 7828.

28000. ?439. 8439. 4. 4. 8435,

30000. 9045, 9044. -1. 1. 9043.

STAHD A'^niZE" RE AD I "r, r 1 . .34 nOTE - irilTlAL CALT^RATTOf]> MO PREVIOUS DATA AVAlLAi^LE FOR CQMPARISOM.

THE FOLLO'.'ING C'LTpPA-rjOM FQU'^TlO'ir rrccRIHEO IN SECTTqI' 7.? OF flST^^ M^jMon

E 74-74, ,;aS FlTT^n TO THE C.^LIPRATK.^| DATA •'^Y THF rpTHOn OF LEAST SOUAPES,

DEFLECTION = (A) + (q)(' OA'^) (OCLOAP SQU'PFD)

V.'HERE A r . 1 f.'=iQ-^7-t-P?

B = .297793+no

C = .102431-06

UNCERTAIriTY = 35.00 L^^F

TENSION LO,''.n TAPLE FOF ?3 DEGPFrs C

DEFLECTION LO^D INTER^OLATTOU TaPLFS

U-^'ITS LPF UNITS LRF UNITS LRF

lOOO. 3299. 1 00. 332. 10. 33.

2':^no. 6645. 200. 663. 20. 66.

3000. 9984. 300. 995. 30. 99.

4000. 13315. 400. 1327. 40. 133. snno. 16639. 500. 1658. 50. 166.

6000. 19956. 600. 1990. 60. 199.

7000. 23264. 700. 23^1 . 70. 232.

8000. 26566. 800. 2653. 80. 265.

- 9000. 29860. 900. 2985. 90. 298.

lOOno. 33147.

^1
riATIOIlAL lii^EAii OF STA^'HARDS FO-^CE

Table 1 - CLTM 10

fALT^^RATTON P AG"^ 4

TRA^!SOUCC^PS VI«^HAY P'DIC 1 °6P"^6

CALIBRATED TO 3u0C0 L?.F TEnSIOr^ APR IL 24 » 1 "^76

CAI. I'^^ATIO"' IM AC^ORDi CE WITH ASTM '/iFTHOn E 74- 74

TENSION mAT^ FO^ 23 OEG^EES

APPL I -L LOAD

Ur.l- L'-T T I 0 JS O'- b'lK ViiD

nilRT'lf^ CAl.I'3P^TI0f

HEVlATToriS FRO'

FITTro riipvF

VALUES

FROM

CH '^r IGE

PU-! 1 RUN 2 RUN 1 PUN ? FITTED

CURVE

por\/Toi

C ALI'^RATTOM

3000. -9. -6. 897.

4 U (J U . 60C0.

11 "i^ iio*z

17aQ. 1.793.

-2. 1

5. 9.

1192.

1784.

o r\ r\ n 10000 . rj 7"» If*

?9-'3. 2977.

-5. -0.

2. 6.

2377,

2971.

1 o n r. rt 14000.

JO 1 1 * 41f>1. 4169.

10. 6.

-2. 6.

3567,

4163.

16000.

18000.

4757. 4767.

5359. 5357.

-4. 6.

-1. -3.

. 4761

' 5360.

20000.

22000.

595=^. 5953.

65^'6. 6555.

-3. -8.

-6. -7.

5961

6562.

24000.

26000.

7156. 7165.

7769. 7776.

-9. -0.

-0. 7.

7165.

7769.

28000.

30000.

8331. 8375.

P9'''5. 8983.

6. 0.

4. 2.

8375,

STAMDVPOIZEf RE'^DIr'G = MOTE - IMITIAL MHS rALIPRATTOMr :\C)

1 .34

PREVIOUS DATA AVAILABLE FOR CON''P'^RIS'^f|.

THE FOLLO... E 74-74

IMP CM..lnRATION EONATTOM, nrccPTRE'^ IN '^ECTTOM 7.? OF ASTM '*''E"^HOO AS P^ITTrn TO THE C Al.IRR." TI'^"' PflTA TH^ Mp-^HOO OF LEAST SOUA'^ES.

DEFLECTION = (A) + (R)(LOA^) + (C)(LO/^r SOU" RP"0)

WHERE A = . J2P^>65+'^?

C = ,29ti?«0 + 00.155834-06

UrjCERTAIf.JTY - 46.00 LPF

TErJSIOrj LOf.n TPPLE Fnp ?3 hFGPE^S C

DEFLE'^Tlori LOAD INTERPOLATTor' ^APLES

UNITS LRF UNITS L"F UN 1*^5 L^F

imn. 334Q. inn. 3^^- in.

2000, 6729. 200. 667. 20. 67.

3000. 10G°7. 300. lOno, 30. lOP.

4000. 13453. 400. 1333. 40. 133. snno. 16798. '^OO. 1666. 50. 167.

6000. 20131. 600. 2000. 60. 200.

70O0. 23452. 700. 23^3. 70. 533.

Bono. 26762. AOO. 2666. 80. 267.

9ono. 30061. QQO. 3000. «50. 3nn.

10000. 33349.
On - Batt - Off . This 3-positlon slide switch is actuated to

provide power to the measurement circuit.

5. OPERATION

This section provides the user with information on the start-up and

operation procedures of the machine.

5.1 Establishing the Operating Temperature

To insure stable operation of the amplifier system after a period

of machine shutdown, it is necessary to activate the temperature control

system of the Instrumentation Module several hours before the machine

will be used. The control temperature for this system is preset at

approximately 50 °C. In addition to the internal temperature monitoring

points at pins D and G of the connector, a copper-constantan thermocouple is attached to the internal electronics. This thermocouple is

accessable under the cover of the small cable elbow on the Module.

1. Turn on the Power Disconnect Switch located on CLTM 1.

2. Turn on all power switches located inside the inboard junction

box on the top of each machine being operated.

3. Adjust the voltage of the heater supply circuit to 150 V using

the autotransformer located in the Power Supply Cabinet on CLTM 6.

4. Monitor the internal temperature of the Instrumentation

Module by reading the voltage between pins D and G of

the Internal Function Connector. A voltage of 3.1 V

indicates that the internal temperature is 50 °C.

5. If temperature changes of the Module are desired, clockwise

rotation of the Temperature Control raises the internal temperature. Refer to Figure 8 for the voltage at pins D and G

corresponding to the internal temperature.

5.2 Applying the Force Level

This section describes the steps to be used in the initial application of load to the specimen.

1. Connect the Portable Transducer Indicator to the Internal

Function Connector. Adjust the SPAN of the INDICATOR to the

1.34 value shown on Table 1. Adjust the BALANCE to null the

meter. Record this balance value as noted in 4.3 above. Set

the Indicator measurement dial to the value corresponding to

the desired load on the specimen. (See the calibration chart

provided for each module. Table 1).

23

2. Apply force to the specimen to null the Transducer Indicator

meter. Three possible means of applying this force are suggested:

a. Turn the adjusting nut of the pullrod where it passes

through the loading frame (Fig. 1).

b. Use a hollow ram jack, such as used to pretension concrete

reinforcing bars, over the threaded pull rod to apply the

initial load.

c. Apply load using the creep machine motor in manual control.

With the motor direction switch set to "forward", operate

the motor while monitoring the transducer indicator.

Care should be taken to prevent a load overshoot using

this method. Because the actuator advances very slowly,

it may be desirable to begin loading using method "a"

above and finish using the motor in this manner.

5.3 Constant Load Operation

This section describes the setting of the controls for automatic

operation of the load maintainer.

1. With the specimen at the desired load, set the Balance - Operate - Gain switch to "Balance". Adjust the "Amplifier

Balance" control to null the output meter.

2. Set the Balance - Operate - Gain switch to "Gain". Adjust the

"Load Cell Zero" control to null the output meter.

3. Set the Balance - Operate - Gain switch to "operate".

4. Set the Hand - Off - Auto switch on the motor controller to

"Auto". The machine will now operate automatically and maintain load within the error bandwidth of the measurement system.

5. To monitor the load, connect the Portable Load Indicator to

the load cell. Set the SPAN and BALANCE adjustments to the

value determined at the time of calibration and recorded on Table 1 for each machine. Refer to Table 1 for the measured

load.

5.4 Changing the Amplifier Gain

If it is necessary or becomes desirable to change the operating

band of the load controller, the following steps should be followed.

25
I 1. With the amplifier balanced and load cell set as in Section

5.3, steps 1 and 2 above, and the Hand - Off - Auto switch in

the HAND position, change the Indicator Measurement dial of

the Portable Transducer Indicator by the amount of the desired

bandwidth. For example, if the desired error bandwidth is

+0.5 percent of capacity, add 150 Ibf (670 N) to the load

indicated on the portable instrument.

2. Increase (or decrease) the machine load to bring the Transducer Indicator into balance.

3. Adjust the GAIN control until the pointer of the Null Meter is

at the plus (or minus) calibration mark (the small round mark

on the dial face. Fig. 9).

.'4. Reset the force to the desired level.

5. Repeat the steps of Section 5.3 and 5.4 in succession until

changes in the BALANCE do not affect the gain output.

5.5 General Notes

If stranded specimens, such as cable, are tested, provision should

be made to prevent rotation of cable fittings. The Instrumentation

Module must remain upright for proper operation.

The creep system has been designed to have some fail-safe features.

Table 2 outlines some foreseeable events and their results.

Table 2 - Failure Events

Event Result

Specimen Fails

+15 V and -15 V

power interrupted.

or

10 V load cell

excitation interrupted,

5 V power interrupted.

Heater power interrupted.

Offscale meter deflection. Motor

will not operate.

No meter deflection. Motor will

not operate.

Temperature control and optical

switch inoperative. Motor will

not operate.

Temperature decreases causing amplifier output to change. Motor will

run resulting in erroneous load.

26
Figure 9 - Meter dial face.

27
NBS-IHA (REV. 7-73)

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. I'lIHi.K A l lON OK l<i:i*OK I' NO. NBSIR 76-1074

2. (lov't Aci i ssjon No.

3. Rec ipient's Accession No.

4. rn 1.1- AND suinn i.i OPERATION MANUAL FOR 30,000 Ibf CONSTANT-LOAD

TESTING MACHINE

»

5. i^ublication Date October 1976

6. I^erforming Organization < odt

7. AU rilOR(S)

Donald E, Marlowe

8. Performing Organ. Report No.

9. PKKFORMING ORC.ANIZATION NAMF AND ADDR KSS NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Proiect/Task/Work Unit No. —213054A

11. Contract /Cirant No.

12. Sponsoring Organization Name and (,ompiete Address (Street, City, State, ZIP)

NASA Langley Research Center

Hampton, Virginia

13. I ype of Report & Period Covered

14. Sponsoring Agency ( ode

15. SUPPLEMENTARY NOTES

16. ABSTRAC'T (A 200-word or less factual summary of most si^ilicant inlormalion. U document includes a significant

bibliography or literature survey, mention it here.)

A 30,000 Ibf (133 kN) constant-load testing machine has been designed, and

ten of these machines have been delivered to the NASA Langley Research Center.

Each machine is equipped with, a self-contained, closed loop load controller whicli

is maintained at a constant temperature, independent of the external ambient

conditions

.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name; separated by semicolons

)

Creep; instrumentation; stress rupture; testing machine.

18. AVAILABILITY [X] Unlimited

1

I For Official Distribution. Do Not Release to NTIS

1 1 Order From Sup. of Doc, U.S. Government Printing Office Washington. D.C. 20-102. SD Cat. No. CH

Order From National Technical Information Service (NTIS)

Springfield, Virginia 22I5I

19. SECURITY CLASS

(THIS REPORT)

UNCLASSIFIED

21. NO. OF PAGES

30

20. SECURITY CLASS

(THIS PAGE)

UNCLASSIFIED

22. Price

$4.00

USCOMM.DC 29042-P74