Chapter 3. OPERATING INSTRUCTIONS - TM-9-6685-202-140018

TM 9-6685-202-14

CHAPTER 3

OPERATING INSTRUCTIONS

Section I. SERVICE UPON RECEIPT OF MATERIEL

3-1. Unpacking

responsibility of the officer in charge to determine

whether the materiel has been properly prepared for

The barometer is received in a wooden box with

service and if it is in condition to perform its assigned

approximate dimensions of 22 by 24 by 70 inches. In

mission when placed in service. Inspect all major units,

order to protect the instrument during shipment, the

assemblies, subassemblies, and equipment to make

vacuum in the mercury tube is released and the mercury

sure that they are properly assembled, secure, clean,

locked in the cistern. The barometer is also removed

and correctly adjusted.

from the mounting platform. Unpack the barometer as

(1) Check all spare parts, tools, and

follows:

equipment to be sure every item is present, in good

condition, clean, and properly mounted and stored.

a. With the box placed horizontally, remove the

(2) Make a record of any missing parts and

top.

malfunctions. Correct any deficiencies as quickly as

possible.

b. Remove coils of cellulose wadding.

(3) Special attention must be directed to the

c. Lift out the inner box and mounting platform.

small parts as they are more likely to become lost. This

d. Remove the 16 by 16-inch plywood squares at

may seriously affect the proper functioning of the

either end of the inner box.

materiel.

e. Withdraw screws securing lid and open inner

(4) Whenever practicable, the operator will

box.

assist in the performance of these services.

f. Withdraw nails securing upper half of yoke,

which retains barometer.

b. Precision Instrumentation. Determine that the

delicate elements of the barometer have been unpacked

g. Remove the two socket head screws securing

without damage or distortion.

base of barometer to end of box.

CAUTION

(1) All switches and controls must function

normally.

Do not grasp the instrument by

either the scale bar, the vernier slide

(2) All vernier scales and other essential

assembly or the cam bar (see figure

markings shall be legible.

1-2). Bending the cam bar a few

(3) The scale, scale rod, thermometer rod,

thousandths of an inch is discernible

and cam bar must not be bent or distorted. These items

as an error in instrument readings.

are straightened to within 0.001 inch and should be so

maintained to retain maximum accuracy.

h. Open

moistureproof

bags

and

remove

desiccant.

3-3. Reporting Discrepancies

i. Remove wax wrapping from the barometer.

a. Refer to paragraph 1-5 and appendix A for

j. Unwrap the mounting platform.

applicable forms, records and reports for inspection. An

k. The barometer is not installed on the mounting

examination of the preventive maintenance records of

platform until after it has been physically inspected and

the barometer will reveal its general maintenance

the mercury tube has been pumped free of moisture.

background. A record of progressive repairs may

indicate that the unit is in excellent condition. All cloth

3-2. Inspection

or paper tags attached to the materiel should be

carefully noted and indicated. Verify the serial number

a. Mechanical Parts.

When a

new

of the materiel with the numbers recorded in the records

reconditioned barometer is received, it is the

of the using personnel.

3-1