Explanation of Columns in the MAC, Section II .

TM 55-1905-223-24-4

Calibrate. To determine and cause corrections to be made or to be adjusted on instruments or test, measuring,

and diagnostic equipments used in precision measurement. Consists of comparisons of two instruments, one of which is

a certified standard of known accuracy, to detect and adjust any discrepancy in the accuracy of the instrument being

compared.

g. Remove/Install. To remove and install the same item when required to perform service or other maintenance

functions. Install may be the act of emplacing, seating, or fixing into position a spare, repair part, or module (component

or assembly) in a manner to allow the proper functioning of an equipment or system.

h. Replace. To remove an unserviceable item and install a serviceable counterpart in its place.. "Replace" is

authorized by the MAC and is shown as the third position code of the SMR code.

Repair. The application of maintenance services', including fault location/troubleshooting, removal/installation,

and disassembly/assembly procedures, and maintenance actions' to identify troubles and restore serviceability to an item

by correcting specific damage, fault, malfunction, or failure in a part, subassembly, module (component or assembly),

end item, or system.

Overhaul.

That maintenance effort (service/action) necessary to restore an item to a completely

serviceable/operational condition as required by maintenance standards in appropriate technical publications [i.e., Depot

Maintenance Work Requirements (DMWR)]. Overhaul is normally the highest degree of maintenance performed by the

Army. Overhaul does not normally return an item to like-new condition.

k. Rebuild. Consists of those services/actions necessary for the restoration of unserviceable equipment to a like-

new condition in accordance with original manufacturing standards. Rebuild is the highest degree of materiel

maintenance applied to Army equipment. The rebuild operation includes the act of returning to zero those age

measurements (hours, miles, etc.) considered in classifying Army equipments/components.

B-3. Explanation of Columns in the MAC, Section II .

a. Column 1, Group Number. Column 1 lists functional group code numbers, the purpose of which is to identify

maintenance-significant components, assemblies, subassemblies, and modules with the next higher assembly. End item

group number shall be "" 0."

Services - inspect, test, service, adjust, align, calibrate, and/or replace.

Fault locate/troubleshoot - The process of investigating and detecting the cause of equipment malfunctioning; the act of

isolating a fault within a system or unit under test (UUT).

Disassemble/assemble - encompasses the step-by-step taking apart (or breakdown) of a spare/functional group coded

item to the level of its least componency identified as maintenance significant (that is, assigned an SMR code) for the

category of maintenance under consideration.

Actions - welding, grinding, riveting, straightening, facing, remachinery, and/or resurfacing.

B-2