Chapter 2. OPERATING INSTRUCTIONS - TM-9-6650-235-13-P0020

ARMY

TM 9-6650-235-13&P

MARINE CORPS

TM-08552A-13&P

CHAPTER 2

OPERATING INSTRUCTIONS

Section I. DESCRIPTION AND USE OF OPERATOR'S CONTROLS AND INDICATORS

2-1.

GENERAL.

This chapter describes, illustrates, and furnishes the

operator with information for operation of the M3

Borescope.

2-2.

CONTROLS AND INDICATORS.

a. Adapter Tube Assembly (1). The adapter tube

assembly (1) houses a variety of controls and indicators

as described in steps 1 thru 6 below.

(1) The eyepiece assembly (2) focuses the

M3 Borescope. Loosen the thumbscrew (3) and rotate

the eyepiece assembly (2) clockwise or counterclockwise

until a clear image is seen. Tighten the thumbscrew (3).

(2) The adapter tube subassembly (4) rotates

within the adapter tube assembly (1) to allow the cannon

EARLY MODEL

bore to be inspected in its entirety while maintaining

electrical continuity with the power source through the

use of built-in electrical contact rings.

(3) Early models have an indicator light (5)

that illuminates only during 115-volt operation. Late

models are not equipped with the indicator light.

(5) On early models two circuit breakers (7) are

provided to break the electrical power in the event of an

(4) The electric light control (6) is a push

electrical short circuit. One circuit breaker controls

on/push off switch that uses a rheostat for controlling the

power in the 115-volt circuit and the other controls power

intensity of the light bulb contained in the illuminating

in the 24-volt circuit. On later models there is only one

head assembly during 115-volt operation only.

circuit breaker to control both 115-volt and 24-volt

circuits.

2-1