MAINTAINABILITY DESIGN TECHNIQUES METRIC - AcqNotes.com

Downloaded from http://www.everyspec.com on 2011-10-29T14:56:01.DOD-HDBK-791(AM)6-2 BASIC CHARACTERISTICSThe characteristics of the label, legend. or markingshould be determined by such factors as (Ref. 4)1. Accuracy of identification required2. Time available for recognition and other responses3. Distance at which device must be read4. Illumination level and color characteristics of theillumination5. Criticality of the label, legend, or marking.Labels and identification should conform to these principles(Ref. 4):1. Labels should give the user the informationrequired to assist in performance of the task.2. Labels should be located consistently throughoutthe equipment.3. Labels should use familiar words; avoid overlytechnical or difficult words.4. Labels should be brief and unambiguous; omitpunctuation.5. Labels should be printed to read horizontally leftto right, not vertically unless the device demands it.6. Labels should be supplemented where necessarywith other coding procedures such as color and shape.7. Labels should be placed where they can be seeneasily, not where other units in the assembly will obscurethem.8. Labels should be large enough so that the operatorsand technicians can read them easily at the normalworking distance.9. Generally, labels should be printed in capitalletters; however, if a label has several long lines. use bothupper- and lowercase letters.10. Labels should be printed in boldfaced lettersonly for short words or phrases that require emphasis.11. Labels should be placed on or very near the itemsthey identify; eliminate confusion with any other itemsand labels.12. Labels should be etched, molded, or embossed.where practical, into the surface for durability rather thanstamped, printed, or stenciled. Decals are acceptable butless desirable.Subsequent paragraphs will expound upon these characteristicsand principles.6-3 TYPES AND USES OFIDENTIFICATION6-3.1 GENERALVarious types of markings are used on equipment.parts, and diagrams to assist operators, technicians, andsupply personnel. The purposes of these markings are to1. Assign a unique nomenclature describing theitem—name, model number, serial number for logisticaland accountability controls. Definitions should be inaccordance with MIL-STD-280 (Ref. 5).2. Identify function.3. Indicale operational and hookup or connectioninstructions to minimize error during operation andrepair and to reduce the need to refer to manuals forcritical information.4. Indicate hazardous conditions.The manner in which these purposes are implemented ispresented in the paragraphs that follow.6-3.2 EQUIPMENT IDENTIFICATIONEquipment in thiis context, to distinguish it from minorsubassemblies and or parts, refers to items issued for aspecific tactical or administrative role e.g. , a tank,truck, artillery piece, or radio. Major subsystems, e.g.,laser range finder for a tank, would also qualify as equipment.(Part identification and marking are discussed inpar. 6-3.5.) Equipment should be marked in accordancewith MIL-STD-130 (Ref. 3) with a permanent identificatione.g., stamping, engruving, molded in, attachedplate, or decal. The identification label should be securelyattached to the equipment and be resistant to water, oil.fuel, cleaning solvents, corrosion, and wear. The permanentplate should allow for a revision in model numberwhen equipment has been retroofitted, e.g., 8-in. Gun.M101, to 8-in. Gun, 101A1.Markings should contain the following information(Ref. .3):1. Item nomenclature and type designation2. Design activity Federal supply code for manufacturers(FSCM) or NATO supply code for manutacturers(NSCM)3. Manufacturer’s identification the manufacturer’sname, FSCM, or NSCM, which identities the place ofmanufacture4. Procurement instrument contract or purchaseorder identification number5. Serial number a unique notation that idenfies itsa single unit of a family of like units; normally assignedsequentially (set Ref. 5)*6. US to denote Government ownership*7. Special characteristics pertinent rating, operatingcharacteristics. and other information neccssary foridentification of item*8. NATO and national stock number ( NSN)*9. Configuration item identifier (CII) the numberassigned to identify a configuration item. When assigned,it is the unchanging base number to which serial numbersare assigned.The items marked with an asterisk (*) are shown onlywhen specified in the contract or purchase order. Fig. 6-1is an example of an identification plate.If the item is warranted by a contract Statement ofWork or other contract clauses, the nature of the warrantyshould be conspicuously displayed by a label. Fig.6-2 is an example of a warranty marking.6-2