1、i f -n * _- MIL-G-81704 93 9 9999906 0122899 I , -. - . MILITARY SPEC1 FICATION GLASS, AIRCRAFT INSTRUMENT, LIGHTING WEDGE AND COVER This specification is mandatory for use by all Departments .and Agencies of the Department of Defense. 1. SCOPE MIL-C-F1 ,o4 24 March 1969 1.1 Scope - This specificati
2、on covers requirements for lighting wedges and cover glasses for use in integrally lighted and unlighted aircraft instruments. 1.2 Classification - Glass covered by this specification shall be of the following Spes: Type I - Colorless optical glass having an index of refraction within the range of 1
3、.47 to 1.55. Type II - Polished plate glass - glass from which surface irregularities have been removed by grinding. be considered equal to polished plate glass. For the purpose of this specification, float glass shall Type III - Clear sheet glass - trmsparent, flat, relatively thin g1:isc having a
4、glossy fire-finished apparently plane and smooth surface, but having :i char- acteristic waviness of surface. 2. APPLICABLE DOCUMENTS 2.1 General - The following documents of the issue in effect on the date of invitation for bids or request for proposal, form a part of this specification to the exte
5、nt specified herein. -. . - . .- -. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-G-L704 93 999990b O122900 4 = SPECIFICATIONS Al ili t ar y MIL- P- 11 6 MIL- C- 67 5 MIL-C-14806 hl1 G O- 1 GS 98 MIL- B-8 13 74 Preservation, Methods of .Coatin
6、g of Glass Optical Elements (An tiref lection) Coating, Reflection Reducing, for Instrument Cover Glasses and Lighting Wedges Optical Elements, Packaging of Barrier Material, Greaseproof, Waterproof, Flexible, High Strength STANDARDS Military AIILSTD-105 Sampling Procedures and Tables for Inspection
7、 by Attributes MIL- STD- 124 1 Optical Terms and Definitions hlS 28105 Cover Glass, Aircraft Instrument Dial 2.2 Other publications - The following drawing forms a part of this specification to the extent specified herein. Unless otherwise specified, the issue in effect on date of invitation for bid
8、 or request for proposal shall apply. DRAWING C. S. Army Iunitions Command C 7641866 Surface Quality Standards for Optical Elements (Copies of spccifirations, standards, drawings and publications required by suppliers in cwnncction with specific procurement func;tions should be obtained from thc pro
9、curing activily or :IS tlircc!t.cti by the contracting officer. ) 63 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-8 17 04 3. REQUIREMENTS 3.1 General - The glass produced for aircraft instruments under this specification shall be capable of
10、meeting the requirement of tests and inspections specified herein unless specifically excluded by contract or drawing requirement s. 3.2 Ternis and definitions - Definitions of terms used herein or in the contract shall be in conformance with MIL-STD-1241. 3.3 Material - The material used to produce
11、 instrument glass shall conform to the requirements specified herein for glass type, color and surface quality. 3.4 Surface defects - Limiting size of surface *iefects shall be designated on the drawing by two numbers which refer to two graded sets of surface quality stmdnrds (Drawing C 7641866). Th
12、e first number shall refer to scratches; the second nuniber shall refer to digs. Bubbles and inclusions shall be classed as surface digs. The size of an irregular shaped bubble or inclusion shall be considered one-half the sum of the ma- imum width and maximum length. Unless otherwise specified, the
13、 following defect limitation for scratches and digs shall apply: Lighting.wedges or light piping glass - Cover glass for unlighted instruments - 40-20 80-50 Cover glass for lighted instruments - 60-20 The combined length of all maximum size scratches shall not exceed one-quarter the diameter of the
14、glass. When a maximum size scratch is present, the maximum combined length of scratches acceptable is calculated as follows : length of scratch diameter of glass =N (Scratch Number) When scratches over # 20 are evaluated, the product N must be less than 1/2 the maximum size scratch allowed. Scratche
15、s less than # 30 are not included in this calculation. When a maximum size scratch is not present, the product N shall not exceed the maximum scratch number. When p1,lished edges or peripheries are required for internal reflection, the edges may be a fire-finish, mold polish, or equivalent, and shal
16、l not be subject to the scratch and dig requirement specified herein. 3.5 Chips - Edge chips .O15 inch or smaller shall be allowed. which do not encroach on the free aperture shall be allowed, providing the chip shall not be visible and objectionable in the assembled instrument. The chips shall not
17、cause light scattering, create an imbalance in the instrument lighting nor interfere with the Larger chips Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-G-81704 93 7997706 01122902 8 RZIGG-81704 sealing of the instrument. Any chip larger than .
18、O20 inch as measured at its largest extremities shall be stoned or sandblasted The sum of the peripheral length of all chips shall not exceed 10% of the length of the edge on which the chips occur. 3.6 Chamfers - All edges may be chamfered .O15 inch maximum st 45 7 15 . On angles less than go“, a .O
19、20 inch flat normal to the face shall be allowed (Fig. 1) to reduce edge chipping. .o20 INCH MAX r -7 - Figure 1. Edges with included angles exceeding 135“ need not be chamfered. 3.7 Striae - Aircraft instrument glass shall have no striae, streaks or cords Clarity - The glass shall not he cloudy or
20、turbid. when inspected in accordance with Section 4 (Test Methods). 3.8 3.9 Indes of refraction - Aircraft instrument glass, including components made from polished plate or sheet glass, shall fall within the indes range of 1.47 to 1.55. The value of the refractive index of the glass will be measure
21、d at the sodium D line 589.3 nanometers. 3.10 Physical measurement - Physical size and tolerances shall conform when practicable to hlS 28105 or shall be as specified in the contract. 3.11 Color - Type II and Type III glass shall be no darker than the green color of an optical cell as outlined in Se
22、ction 4 (Test Methods). 3.12 Coatings - Where an antireflection coating is required, instriiiiieiit glasses shall be coated on all glass-to-air surfaces as specificd in the contract with iiirii1siiiii.r fluor ide co n fo r ni ing to MI L- C - G7 5 o r ni ul ti plc - 1 ayer , 1 ow- r c flec ti o n co
23、 at i iig CO II fi) i* niiii g to mL-C-14806. 4. QUALITY ASSURANCE PROWTONS 4.1 Responsibility for inspection - Unless otherwise specified in the contract or purchase order, the supplier is responsible for the performance of all inspection requirements as specified herein. Except as otherwise specif
24、ied in the contract or order, the supplier may Use his own or any other facilities suitable for the perforiiiancr. of the inspection requirements specified herein, unless disapproved by the Govei-nnient. The Government reserves the right to perform any of the inspections set forth in tlic specificat
25、ion where such inspections are deemed necessary to assure supplies 2nd services conform to prescribed requirements. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-41 II_ - * NIL-G-8170q 73 7777906 0122703 T 9 MIL- G- 8 1704 4.2 Inspection provisions
26、 - . 4.2.1 Submission of product - Unless otherwise specified by the contracting officer, inspection lot size, lot formation and presentation of lots shall be in accordance with “Submission of Product“ provisions in MIL-STD-105. 4.2.2 Examination and tests - 4.2.2.1 Final acceptance inspection - The
27、 classification of defects in Table I constitute the minimum inspection to be performed by the supplier prior to government acceptance or rejection by item or lot, Table I - Classification of Defects Level II of Table I, Sampling Plan IIA of MIL-STD-105 Major: A. Q. L. 1.0% defective Surface Defects
28、 3.4 chips 3.5 Chamfers 3.6 Striae 3.7 Clarity 3.8 Color 3.10 Requirements Physical measurements 3.9 Test Procedures 4.4.1 4.4.2 4.4.3 4.4.4 4.4.5 4.4.6 4.4.7 4.2.2.2 Material certification - Unless actual performance tests are specified in the contract, the supplier shall certify that the material
29、meets the requirements of 3.8. 4.2.3 Acceptance and rejection - Rejected lots shall be screened for all defective characteristics. Removal or correction of defective units and resubmission of rejected lots shall be in accordance with “Acceptance and Rejection“ as specified in RIIGSTD-105. 4.3 Test c
30、onditions - 4.3.1 Visual - Unless otherwise specified, all visual tests shall be restricted to the unaided eye within a 60“ cone of visibility at a distance of 18 f 2 inches. 4.4 Test methods - 4.4.1 Surface Defects - Inspection for surface defects shall be performed in accordance with the method ou
31、tlined in Figure 2, and using scratch and dig comparison 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Y hIIL-G-81704 T T- - 5 1 -v ed rw o a, II) 5 O c, d a, d cd k cd a a *d i3 d d d a a c! m w I3 O x Provided by IHSNot for ResaleNo reproductio
32、n or networking permitted without license from IHS-,-,- -7- - MIL-G-L70 73 777770b 0322705 3 MIL-G- 8 1704 stmdards (DrawingC 7641866). Standards for use in testing for scratches and digs shall be furnished by the procuring agency, which shall procure them from the Frankford Arsenal, ridge and Tacon
33、y Streets, Philadelphia, Pennsylvania 19137. instrument glass rejected for visual defects may be reinspected in a fixture where the illumination of the part is identical to that in the instrument. If the defect, when illuminated, falls within acceptable scratch or dig standards, the part will then b
34、e considered acceptable. 4.4.2 Chips - Glass shall be examined by transmission or reflection to determine Chamfers - Unless otherwise specified, the chamfer dimension shall be Striae - There shall be no visible striae, streaks or cords when viewed ClariQ - Glass which is cloudy or turbid shall be re
35、jected. Physical measurements - Components shall be checked for compliance with the mechanical dimensions on the drawings using standard measuring equipment. Caution should be exercised to preclude the possibility of scratching either glass or coating during measurement. acceptance against requireme
36、nt 3.5. measured along the length of the part, not along the slope of the chamfer. in the direction of maximum visibility, as shown in Figure 2. 4.4.3 4.4.4 4.4.5 4.4. G Color - When viewed perpendicular to the parallel surfaces of the test - 4.4.7 cell against a white background, the glass color sh
37、all be no darker than the green of the test cell indicated below. Standard Solution 3.890 gm of copper chloride (CU C12 - 2 H20) 2.644 gm of nickel chloride (Ni C12 6 HsO) 1.330 gm of cobolt chloride (Co C1 - 6 H20) 2 20 ml of 1-N hydrochloric acid 980 nil of distilled water Optical C ell Optical Ab
38、sorption Cell $5-987 (Pyrex body and windows, Class 1) American Instrument Co. , Inc., Silver Spring, Md. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-G-3704 73 m 777770b 0322706 5 m MIL-G-81704 5. PREPARATION FOR DELIVERY 5.1 Packaging, pack
39、ing and marking - Packaging, packing and marking of aircraft instrument glass lighting wedges and covers shall be in accordance with MIL-0-16898 except where otherwise specified herein. 5.1.1 Levels A and B - Wrapping of individual wedges or covers shall be as specified in MIL-0-16898, except that t
40、he wrapper shall be 10# Kraft Nontarnishing Paper or equivalent and shall be closed with a double fold and undertuck without tape. The unit packaging shall be in accordance with Method 1C-3 of MIL-P-116, except that the fibre-board stiffener may be omitted. The bag utilized for this method shall be
41、fabricated of heat-sealable polyethylene or equivalent and shall be heat-sealed. 5.1.2 Intermediate packing - The intermediate packing shall be as specified in MIL-0-16898 except that the box shall be of fibre-board conforming to the construction requirements of the Nationl Motor Freight Classificat
42、ion. Box closure shall also be in accordance with the National Motor Freight Classification. 5.1.3 Outer packing - The outer packing shall be in accordance with MIL-0- 16898, Level llC“. 5.1.4 Marking - Marking shall be in accordance with sound commercial practices. 5.2 Inspection - Packaging and pa
43、cking defects and tests listed in MIL-O- 16898 which are not applicable due to the exceptions in 5.1.1 through 5.1.4 shall be deleted from the inspection procedure. 6. NOTES 6.1 Intended use - The glass covered by this specification is intended for use as aircraft instrument cover glass and lighting
44、 wedges. t 6.2 Ordering data - Procurement documents should specify the following: (a) Title, number, and date of this specification. (b) Type of glass desired. (c) Type of antireflection coating desired. (d) Selection of applicable levels of packaging and packing. Custodians : Navy - AS Air Force - 11 Army - GL Re view Activites : Navy - AS Air Force - 11, 84, 85 Army - GL, AV, MD .c_-_ - - _ Preparing Activity: Navy - AS (Project No. 9340-0020) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
