n. S. WARDEPT. TECHNICAL MAKOAL 8~62/, 
SirjSOiaAL MACHINE TIMKI4 
WAR DEPARTMENT TECHNICAL MANUAL 
SINUSOIDAL 
MACHINE 
WAR DEPARTMENT 
1 SEPTEMBER 1944 WAR DEPARTMENT TECHNICAL MANUAL 
T M 8-62 4 
SINUSOIDAL 
MACHINE 
WAR DEPARTMENT • 1 SEPTEMBER 19 44 
United States Government Printing Office 
Washington : 1944 
For sale by the Superintendent of Documents, Washington, D. C. WAR DEPARTMENT, 
Washington 25, D. C., 1 September 1944. 
TM 8-624, Sinusoidal Machine, is published for the information and 
guidance of all concerned. 
[A. G. 300.7 (28 Jul 44).] 
order of the Secretary of War; 
G. C. MARSHALL, 
Chief of Staff. 
Official: 
J. A. ULIO, 
Major General, 
The Adjutant General 
Distribution : 
Armies (5); Corps (5); Sv C (10); Dept (10); ID 8 (2); IR 8 (2); 
T of Opn (10); Base Comd (10); Med Tech Sch (2); Med Dep (25) 
except St. Louis Dep (50). 
ID 8: T/O 8-550. 
IR 8: T/O 8-560. 
For explanation of symbols, see FM 21-6. 
II CONTENTS 
Chapter 1. Introduction 
Paragraph 
Page 
Section I. General. 
Scope 1 1 
11. Description and data. 
Description 2 1 
Data 3 1 
Chapter 2. Operating instructions 
Section I. General. 
Scope 4 3 
II. Service upon receipt of equipment. 
Unpacking 5 3 
Assembling 6 3 
III. Controls and instruments. 
Controls 7 3 
Instruments 8 6 
IV. Operation. 
Operation 9 6 
Chapter 3. Maintenance instructions 
Section I. General. 
Scope i o 8 
//. Preventive maintenance services. 
Dusting ii 8 
Electrical connections 12 8 
III. Trouble shooting. 
Milliampermeter burned out 13 8 
Testing patient’s cords 14 8 
Testing electrode pads 15 8 
Rectifier tube 16 8 
Vibrator screw 17 9 
Choke coil 18 9 
Line transformer rheostat 19 9 
Appendix I. Shipment and storage 10 
II. Standard nomenclature list of parts n 
III CHAPTER 1 
INTRODUCTION 
Section I. GENERAL 
1. SCOPE, a. These instructions are published for the information and 
guidance of all personnel charged with the operation and maintenance of 
The McIntosh Electric Corporation Model No. 5018 of Sinusoidal Machine, 
Portable, for Galvanic, Faradic and Rapid Sinusoidal Currents, 110-Volt, 
60-Cycle, Medical Department item No. 7132005 (fig. 1) in the field. 
They contain information on the operation and maintenance of the equip- 
ment with illustrations showing the various parts referred to in the instruc- 
tions. They are arranged in three chapters: Chapter 1—Introduction; 
Chapter 2—Operating Instructions; Chapter 3—Maintenance Instructions. 
b. A Standard Nomenclature List of parts for this item is included in 
appendix II. 
Section II. DESCRIPTION AND DATA 
2. DESCRIPTION. The Sinusoidal Machine, Portable, is a light, self-con- 
tained unit completely inclosed in a carrying case. Necessary accessories 
are contained in a compartment in the lid of the carrying case. The appa- 
ratus delivers separately a galvanic, faradic, and rapid'sinusoidal current, 
each of which is ground-free and suitable for therapeutic uses, particu- 
larly the testing of nerves and the testing and treating of muscles. 
3. DATA. a. Performance. The Sinusoidal Machine, Portable, is designed 
to operate on no-volt, 60-cycle, a-c or d-c current, depending on the 
available supply. A current selector switch is provided to make the neces- 
sary adjustment for operation on either type of current. At full load, the 
machine consumes a maximum of 6 amperes. 
b. Manufacturers. The Sinusoidal Machine, Portable, is manufactured 
by McIntosh Electric Corporation, Chicago, Illinois, Model No. 5018. 
Information relative to the type of equipment manufactured by 
the J. Beeber and Company will be incorporated in a change of the 
manual at a later, date. 
1 1. 7R03276 CASE, CARRYING, COMPLETE: 
Assembly; with hasps and handle. 
2. 7R83236 HANDLE, INDICATOR, PLASTIC. 
3. 7R03212 VIBRATOR,COMPLETE:Assembly. 
4. 7R032C6 MILLIAMPERMETER. 
5. 7R03202 TUBE, RECTIFIER. 
6. * ACCESSORY COMPARTMENT. 
7. 7R03240 POST, BENDING, COMPLETE: As- 
sembly; for patient’s cord. 
8. 7R03242 SWITCH, POLARITY, COMPLETE: 
Assembly. 
9. 7RG3244 SWITCH, METER SCALE SELEC- 
TOR, COMPLETE: Assembly. 
* IJo spare part number. (Component part of 7R03276, CASE, CARRYING, COMPLETE.) 
Figure i. Portable Sinusoidal Machine, manufactured by the McIntosh Electric 
Corporation. 
2 CHAPTER 2 
OPERATING INSTRUCTIONS 
Section I. GENERAL 
4. SCOPE. This chapter contains information for the guidance of the 
personnel responsible for the operation of this equipment. It contains 
information on the operation of the equipment with the description and 
location of the controls and instruments. 
Section II. SERVICE UPON RECEIPT OF EQUIPMENT 
5. UNPACKING. To unpack the sinusoidal machine, open the shipping 
box carefully. Remove packing materials. Grasp the handle of the carrying 
case and lift the apparatus from the shipping box. 
6. ASSEMBLING, The apparatus is shipped completely assembled except 
for inserting the male plug, SR00026 (fig. 3), of the line cord into the power 
supply receptacle and the female receptacle, SR00025 (fig. 3), of the line 
cord into the recessed plug at the back of the carrying case. The patient 
cables must be removed from the compartment in the carrying case lid 
and attached to the apparatus by inserting the patient’s cord tips into the 
binding posts, 7R03240 (fig. 1). The machine is then ready to have the 
electrodes applied. The application of the electrodes is described in 
Section IV. 
Section III. CONTROLS AND INSTRUMENTS 
7. CONTROLS, a. Polarity switch. The polarity switch, 7R03242 (fig. 1), 
is located between the binding posts, 7R03240 (fig. 1), at the front of the 
control panel, 7R03264 (figs. 1 and 2). It determines the polarity of the 
electrodes used. When operating on alternating current, the polarity switch 
should always point toward the positive electrode binding post. 
b. Meter scale switch. The meter scale switch, 7R03244 (fig. 1), permits 
the selection of the scale desired on the milliampermeter, 7R03206 (figs. 1 
and 2). When a galvanic current of less than 12 milliamperes is required, 
snap the meter scale switch to the “Low” position and read the current on 
the o to 12 scale of the milliammeter. When a galvanic current of more than 
12 milliamperes is required, snap the meter scale switch to “High” and 
read current on the o to 120 scale. 
c. Current selector switch. The current selector switch is used to select 
which of the three available wave forms will be used on alternating current 
and on direct current. Before connecting the machine to the supply line, 
determine whether the supply current is alternating or direct. Turn the 
selector switch control handle, 7R03236 (fig. 1), to the “a-c” or “d-c” side 
and insert the stop pin used in conjunction with the switch. This prevents 
turning switch to the wrong side and thus safeguards the unit against 
possible damage. On the alternating current side of the selector switch, 
3 1. 7R03266 BASE, MOUNTING, METAL. 
2. * TUBE MOUNT. 
3. 7R03202 TUBE, RECTIFIER. 
4. 7R03262 CONTROL, PATIENT CURRENT, 
COMPLETE: Assembly. 
5. 7R03264 PANEL, TOP, PLASTIC. 
6. 7R03212 VIBRATOR,COMPLETE:Assembly. 
7. 7R03206 MILLIAMPERMETER. 
8. 7R03260 BOARD, MODALITY SELECTOR 
SWITCH, COMPLETE: Assembly. 
9. 7R032S6 RESISTOR, ISO OHM. 
10. 7R03204 CAPACITOR, ELECTROLYTIC. 
11. 7R03248 COIL, FARADIC. 
12. 7R03272 TRANSFORMER, LINE. 
13. 7R03246 BLADE, MODALITY SELECTOR. 
COMPLETE; Assembly. 
14. 7R032S8 COIL, CHOKE. 
*No spare part number. (Component part of 7R032S6, BASE, MOUNTING METAL.) 
Figure 2. Sinusoidal Machine, manufactured by McIntosh Electric Corporation 
inside view. 
4 1. SR00025 PLUG, FEMALE, TWO PRONG 
G E GC-3C3 
2. SR00026 PLUG, MALE, SMALL, TWO 
PRONG. 
3. SR80072 CORD, NEOPRENE, NO. 18, TWO 
CONDUCTOR. 
4. 7R03214 CORD, PATIENT’S, COMPLETE: 
Assembly. 
5. 7R03220 HANDLE, WOODEN, COMPLETE: 
Assembly. 
6. 7R03218 ELECTRODE, % INCH DISC, 
NICKEL PLATED. 
7. 7R03224 ELECTRODE, ASBESTOS PAD, 
4 X 6 INCHES. 
8. 7R03226 ELECTRODE, SPONGIO PAD, 3V2 
INCH. 
9. 7R03228 HOLDER, NEEDLE, COMPLETE; 
Assembly; with magnifying glass. 
10. 7R03230 ELECTRODE, NEEDLE, BULBOUS, 
FINE. 
11. 7R03232 ELECTRODE, NEEDLE,BULBOUS, 
MEDIUM. 
12. 7R03234 ELECTRODE, NEEDLE,BULBOUS, 
COARSE. 
Figure 3. Accessories, Sinusoidal Machine, manufactured by McIntosh Electric 
Corporation. 
5 three wave forms are available: galvanic, secondary faradic, and rapid 
sinusoidal. On the direct current side of the selector switch, three wave 
forms are also available: galvanic, secondary faradic, and primary faradic. 
Never attempt to use the current forms listed under alternating current 
when the machine is operating on direct current. This will injure the elec- 
trical circuit of the apparatus. 
d. Patient current control. The patient current control, 7R03262 (figs. 1 
and 2), increases or decreases the milliampere output of the apparatus. 
It is calibrated on an arbitrary scale from “Off” on the left to “180” on 
the right. It is a convenient control panel method of regulating patient 
dosage of all the current forms. 
e. Vibrator screw. The vibrator screw, 7R03212 (figs. 1 and 2), is 
located at the back of the control panel. From time to time it may need 
adjustment as continued use of the apparatus oxidizes and wears down the 
contact points. To adjust these points, turn the vibrator screw so its tung- 
sten contact just touches the tungsten contact of the spring. 
8. INSTRUMENTS, a. Milliampermeter. A direct current milliampermeter, 
7R03206 (figs. 1 and 2), is located at the left rear of the control panel. 
It operates only when galvanic current is used. This meter is provided with 
two scales, a low scale calibrated from “o” to “12” milliamperes and a high 
scale calibrated from “o” to “120” milliamperes. The position of the meter 
scale switch determines which scale on the milliampermeter shall be read. 
This procedure is discussed thoroughly in paragraph 7b. 
b. Rectifier tube. The rectifier tube, 7R03202 (figs. 1 and 2), must be 
installed when the equipment is used on alternating current. It should be 
inserted on its socket through the hole at the right rear of the control panel. 
The tube will fit only one way in the socket with the heavy prongs toward 
the rear of the machine. It is essential that the tube be pushed down 
tightly to obtain proper contact. 
Section IV. OPERATION 
9. OPERATION, a. To determine polarity when operating on direct cur- 
rent. (1) Set current selector switch on “Galvanic from line,” which is 
No. 1 on the d-c side of the current selector switch. 
(2) Set meter scale switch, 7R03244 (fig. 1), to “High” position. 
(3) Set patient current control, 7R03262 (figs. 1 and 2), to “Off” 
position. 
(4) Turn patient current control very slowly to right and note the 
direction the meter indicator points. If the indicator points toward the 
right, the polarity is correct. If the indicator pointer moves toward the left 
of the “o” mark, the polarity is wrong. Correct the polarity by reversing 
the male plug in the current supply socket. 
(5) Recheck polarity by repeating the procedure outlined above. 
b. Preparation of electrode pads, (i) Soak pads to be used in a hot 
saline solution or hot water for about to minutes. 
(2) Squeeze excess solution or water out of pads on a towel laid flat on 
the table. 
c. To prepare needle electrodes for operation. (1) Open the chuck of 
the needle holder with magnifying glass, 7R03228 (fig. 3), by turning 
clockwise when holding the needle holder in operating position. 
6 (2) Push the needle electrode selected through the back of the chuck 
until the needle protrudes about x/2 inch from the chuck. 
(3) Tighten the chuck. 
(4) Connect the needle holder with the needle inserted to the negative 
or black cord. 
d. Connecting of patient’s cords, 7R03214 (fig. 3). (1) The patient’s 
cords should be connected so that the red cord is in the positive binding 
post, 7R03240 (fig. 1). 
(2) The black cord should be connected in the negative binding post, 
7R03240 (fig. 1). 
(3) The polarity of the binding posts is determined by the polarity 
switch, 7R03242 (fig. 1), which points in the direction of the positive 
binding post. 
e. To determine wave form. To determine wave form, turn indicator, 
7R03236 (fig. 1), on current selector switch to position 1, 2, or 3, depending 
on the wave form desired. Patient current control must always be at “Off” 
during this operation. 
f. To control patient’s dosage. (1) To increase dosage, turn patient 
current control indicator, 7R03236 (fig. 1), to right. 
(2) To decrease dosage, turn patient current control to left. 
(3) Milliamperes being delivered by the machine are registered on 
D. C. Milliampermeter, 7R03206 (figs. 1 and 2), when galvanic current is 
being delivered. When the other wave forms are being delivered, the meter 
will not register. 
g. Use of wave forms, (i) Galvanic current is used for nerve testing or 
destructive action on hair or tissue. 
(2) Faradic current is used for testing nerves and testing and treating 
muscles. 
(3) Rapid sinusoidal current is used mainly for inhibition of the sciatic 
nerve in sciatica. This wave form is available on the alternating current 
side only. 
7 CHAPTER 3 
MAINTENANCE INSTRUCTIONS 
Section I. GENERAL 
TO. SCOPE. This chapter contains information for first echelon mainte- 
nance of the portable sinusoidal machine. 
Section II. PREVENTIVE MAINTENANCE SERVICES 
11. DUSTING. Keep the machine clean and free of dust by frequently 
dusting with a damp cloth. 
12. ELECTRICAL CONNECTIONS. Keep all connections on line cord and 
patient’s cords, 7R03214 (fig. 3), bright and clean by occasional sanding 
with a fine grade of emery cloth and wiping with a clean rag. 
Section III. TROUBLE SHOOTING 
13. MILLIAMPERMETER BURNED OUT. No galvanic current will come 
through if the milliampermeter is burned out, as the milliampermeter is 
connected in series in the circuit. The meter should be replaced. If a 
replacement meter is not available, short the meter out by putting a wire 
across the meter binding posts, 7R03240 (fig. 1). 
14. TESTING PATIENT’S CORDS. To test the patient’s cords, 7R03214 
(fig. 3), set the current or modality selector switch to “Galv.” and test 
each cord separately by inserting the cord tip and turning the current 
control to secure a given milliampere reading. Grasp the cord near the 
cord tip and shake it, observing the meter indicator needle. If the needle 
moves, there is a broken wire connection. The wire should be cut off above 
the broken connection and again attached to the cord tip. 
15. TESTING ELECTRODE PADS. To test the electrode pads, insert the 
patient’s cords, 7R03214 (fig. 3), and short circuit them so that the current 
passes from one binding post, 7R03240 (fig. 1), to the other directly through 
both cords. With the meter set on ‘"High” scale, turn the current or power 
control until the meter registers 80 milliamperes. After the pads have been 
soaked thoroughly for at least 10 minutes in a saturated saline solution, 
attach to the patient’s cords, placing the canvas sides of the pads together 
and leaving the current controller in the same position as before. There 
should not be a drop of more than 20 milliamperes in the meter reading. 
If the current drops to less than 60 milliamperes, the pads should be 
replaced. 
16. RECTIFIER TUBE. In operation, the rectifier tube, 7R03202 (figs. 1 
and 2), lights up. Excessive heating of the tube shows that the electrolytic 
capacitor is defective or burned out. The capacitor can be removed by 
8 pulling it from its socket. When not in use, the tube should be removed 
from the socket and carefully replaced in accessory compartment. 
17. VIBRATOR SCREW. The vibrator screw, 7R03212 (figs. 1 and 2), may 
need adjusting so that its tungsten contact just touches the tungsten contact 
of the spring, as continued use will oxidize and wear down these points. 
If the faradic current fails to come through after adjusting the vibrator 
screw, the faradic coil may be burned out. 
18. CHOKE COIL. To test the choke coil, 7R03258 (fig. 2), connect a 
lamp in series across the terminals. If the coil is all right, the lamp will 
light up weakly. If the lamp is bright, the choke coil is shorted. 
19. LINE TRANSFORMER RHEOSTAT. The line transformer rheostat may 
be tested with any standard a-c voltmeter. The 125 OHM resistor should 
be tested with an ohmmeter. 
9 APPENDIX I 
SHIPMENT AND STORAGE 
The Sinusoidal Machine, Portable, is a light, self-contained unit completely 
inclosed in a carrying case. It requires additional protection, however, for 
shipment and storage. 
1. Disassembling. To disassemble the machine for packing, remove the 
patient’s cables from the receptacles in the control panel. Remove the line 
cord from the power source and from the receptacle in the back of the 
carrying case. Pack the line cord patient’s cables and electrodes in the lid 
of the carrying case. 
2. Packing. To pack the sinusoidal machine, place it in a wooden or stout 
kraftboard box. Pad well with paper or rags to prevent shifting in transit. 
3. Storage. No special instructions are necessary for storage. However, the 
sinusoidal machine is a delicate electrical instrument, subject to damage 
from sharp jolts, jarring, or dropping, and it must be handled with care. 
10 APPENDIX II 
STANDARD NOMENCLATURE LIST OF PARTS 
(McIntosh Electric Corporation Model No. 5018) 
Common parts 
Fig. 
No. 
Med. 
Dept. No. 
Nomenclature 
— 
SR00003 
SCREW, 8—32 X Y INCH, R. H. M. Used to secure trans- 
former cover. 
* 
3 
SR00025 
PLUG, FEMALE, TWO PRONG, G. E. GC--3C3. 
* 
3 
SR00026 
PLUG, MALE, SMALL, TWO PRONG. 
SR00042 
WASHER, SCREW SIZE 6. 
— 
SR00043 
NUT, 6 X 32, HEX. 
SCREW, 4-36 X H INCH, R. H. M. 
* 
— 
SR00047 
* 
3 
SR00072 
CORD, NEOPRENE, NO. 18, TWO CONDUCTOR. 
SR00105 
SCREW, 6-32 X H INCH, R. H. M. 
* 
— 
S Root 08 
SCREW, 6-32 X Y INCH, R. H. M. Used in vibrator. 
— 
SR00142 
SCREW, 10-32 X Y INCH, R. H. M. Used to secure mounting 
base to carrying case. 
— 
SR00151 
WASHER, LOCK, SCREW SIZE 10. Used in mounting. 
* 
— 
SR00152 
WASHER, LOCK, SCREW SIZE 8. 
— 
SR00153 
WASHER, LOCK, SCREW SIZE 6. 
— 
SR00158 
WASHER, SHAKEPROOF, SCREW SIZE 6, INT. Used in 
vibrator assembly. 
— 
SR00229 
WASHER, LOCK, SCREW SIZE Y- Used in transformer 
mounting. 
— 
SR00230 
NUT, Y\ X 20, HEX. Used in transformer mounting. 
NUT, 4 X 36, HEX. Used to secure milliammeter. 
* 
— 
SR00269 
— 
SR00293 
WASHER, SCREW SIZE Y- Used in mounting base. 
— 
SR00304 
WASHER, SCREW SIZE 8. 
— 
SR00330 
NUT, 10 X 32, HEX. Used in mounting base. 
* 
— 
SR00399 
NUT, CAP, 6 X 32, HEX. Used in vibrator assemblv. 
♦ 
— 
SR00402 
SCREW, 4—36 X Y INCH, FL. H. M. Used in vibrator assem- 
bly. 
— 
SR0041 2 
PIN, COTTER, %2 INCH DIA., K INCH LENGTH. Used 
in control shafts. 
— 
SR00427 
BRACKET, RESISTOR, OHMITE NO. 12. 
— 
SR00431 
WASHER, FINISHING, SCREW SIZE 8, COUNTERSUNK. 
Used in mounting top panel. 
* 
— 
SR00432 
SCREW, 5 X Y INCH, R. H. WOOD. Used to secure power 
supply receptacle. 
— 
SR00433 
SCREW, 8—32 X Y INCH, O. H. M. Used to secure top panel. 
— 
SR00434 
SCREW, Y-20 X 3 INCH, R. H. M. Used to secure trans- 
former. 
— 
SR00435 
NUT, Y X 20, SQUARE. Used to secure transformer. 
— 
SR00436 
SCREW, 6-32 X H INCH, R. H. M. Used in condenser. 
— 
SR00437 
SCREW, 10X iY INCH, R. H. WOOD. 
* 
SR00572 
SETSCREW, 8-32 X H INCH, HEADLESS CUP POINT. 
Used in indicator handles. 
11  
Fig. 
No. 
Med. 
Dept. No. 
Nomenclature 
* 
1-2 
7R03202 
TUBE, RECTIFIER. 
♦ 
2 
7R03204 
CAPACITOR, ELECTROLYTIC. 
* 
1-2 
7R03206 
MILLIAMPERMETER. 
* 
— 
7R03208 
CONDENSER, PAPER WOUND. 
* 
1-2 
7R03212 
VIBRATOR, COMPLETE: Assembly; includes screw, spring, 
and yoke. 
* 
3 
7R03214 
CORD, PATIENT’S, COMPLETE: Assembly. 
♦ 
3 
7R03216 
ELECTRODE, ASBESTOS PAD, 4X6 INCHES. 
* 
3 
7R03218 
ELECTRODE, # INCH DISC, NICKEL PLATED. 
* 
3 
7R03220 
HANDLE, WOODEN, COMPLETE: Assembly. 
* 
3 
7R03226 
ELECTRODE, SPONGIO PAD, INCH. 
* 
3 
7R03228 
HOLDER, NEEDLE, COMPLETE: Assembly with magnify- 
ing glass. 
* 
3 
7R03230 
ELECTRODE, NEEDLE, BULBOUS, FINE. 
♦ 
3 
7R03232 
ELECTRODE, NEEDLE, BULBOUS, MEDIUM. 
* 
3 
7R03234 
ELECTRODE, NEEDLE, BULBOUS, COARSE. 
♦ 
i 
7R03236 
HANDLE, INDICATOR, PLASTIC. 
♦ 
— 
7R03238 
PIN, STOP. 
i 
7R03240 
POST, BINDING, COMPLETE: Assembly for patient’s cord. 
i 
7R03242 
SWITCH, POLARITY, COMPLETE; Assembly. 
I 
7R03244 
SWITCH, METER SCALE SELECTOR, COMPLETE; As- 
sembly. 
2 
7R03246 
BLADE, MODALITY SELECTOR, COMPLETE; Assembly. 
2 
7R03248 
COIL, FARADIC. 
— 
7R03250 
NUT, 6-32 X 5/($ INCH, HEX. Used in vibrator assembly. 
— 
7R032^2 
NUT, 4-36 X yi INCH, HEX. Used in vibrator assembly. 
— 
7R03254 
RECEPTACLE, RECESSED, MALE, TWO PRONG. For 
power supply. 
2 
7R03256 
RESISTOR, 150 OHM. 
2 
7R032S8 
COIL, CHOKE. 
2 
7R03260 
BOARD, MODALITY SELECTOR SWITCH, COMPLETE. 
Assembly. 
1-2 
7R03262 
CONTROL, PATIENT CURRENT, COMPLETE: Assemblv. 
1-2 
7R03264 
PANEL, TOP, PLASTIC. 
2 
7R03266 
BASE, MOUNTING, METAL. 
— 
7R03268 
COVER, TRANSFORMER, METAL. 
— 
7R03270 
BOARD, TERMINAL, TRANSFORMER, COMPLETE: 
Assembly. 
2 
7R03272 
TRANSFORMER, LINE. 
— 
7R03274 
CLAMP, PAPER WOUND CONDENSER. 
I 
7R03276 
CASE, CARRYING, COMPLETE; Assembly: with hasps and 
handle. 
Uncommon parts 
* To be requisitioned, when required, from the supply depot. t 
No asterisk indicates that the item is not stocked as a spare part, but can be obtained by special 
requisition. 
U. S. GOVERNMENT PRINTING OFFICE: 1944—604443 
12