CHAPTER 2. DESCRIPTION AND DATA

TM 9-4931-381-14&P-1

CHAPTER 2

DESCRIPTION AND DATA

Section I. FUNCTIONAL DESCRIPTION

2-1.

Overall Function.

General. The test set is a computer controlled test device used by Direct

Support/General Support repairpersons. Its purpose is to find faulty modules or parts within

the M I Tank Thermal Imaging System (TIS) and the M60A3 Tank Thermal Sight (TTS) that

have been removed from the tank. The test set measures actual voltage and frequency

outputs from the assemblies being tested. It then compares these measurements with

values stored in the test set computer memory. If the measured value agrees with the

stored value, the next test maybe performed. Sometimes the test set will automatically

do the next test. At other times you must perform some action before the next test

starts. The test set provides short messages to you in the form of information, commands, or

questions. These messages appear on the test set MESSAGE DISPLAY. Questions are answered

by pressing the YES or NO pushbuttons on the test set control panel. Most commands are

carried out by operating switches and controls on the test set panel. However, some

commands require that you operate controls on the equipment being tested. If a measured

value disagrees with a stored value in the test set computer, the test set display will tell you to

replace a faulty module or part.

b. Automatic Self Test. The test set has a built-in automatic self test function.

This function tests the digital subsystem in the test set each time the ON-OFF switch is set to

ON. If the self test is failed, the test set cannot be used until repaired. If the self test is

successful, the MESSAGE DISPLAY will say:

AUTOMATIC SELF TEST COMPLETED

RUN OAST?

This tells you the digital subsystem is working properly. Then you have the option of running

the operator assisted self test (OAST).

c. Operator Assisted Self Test (OAST) Function. This function tests the circuit card

assemblies, the modules, and the panel controls and indicators in the test set. Although the

OAST is optional, it is a good idea to run it every time the TEST SET POWER switch is set to

ON. This will ensure that all parts of the test set are working properly. If any corrections are

needed, a fail code (volume Ill, chapter 7) will appear on the MESSAGE DISPLAY telling you

what is wrong with the test set and how to fix it. Once the OAST has run completely, the test

set is ready to test tank thermal units.

d. External Power Supply. A variable +18 to +30V dc, 50 amp, regulated power supply

(model HP6269B or equivalent) is required to operate the test set. Refer to volume III, chapter

3 for test equipment procedures index.

Volume 1

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