1、MIL-F-23LI2LIA 32 777770b 0303343 b MIL-F-21424A (OS ) 31 Julv 1 975 SUPERSEDING MIL-F-2 14 2 4 (Nord) 13 June 1958 MILITARY SPECIFICATION FILTERS , POLARIZING (FOR OPTICAL INSTRUMENTS) This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1
2、This specification covers polarizing filters for use in optical instruments. * .k 2. APPLICABLE DOCUMENTS 2.1 for bids or request for proposal, form a part of this specification to the extent specified herein: The following-documents, of the issue in effect on dateof invitation SPECIFICATIONS Milita
3、ry MIL-B-131 Barrier Materials , Water Vaporproof , Flexible,Heat-Sealable MIL-G-17 4 Glass, Optical MIL-0-13830 Optical Components for Fire Control Instruments; General Specification Governing the Manufacture, Assembly, and Inspection of MIL-P-16898 Optical Elements; Packaging of MIL-A-392 O Adhesi
4、ve , Optical , Thermosetting FSC 1240 , Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-(Copies of specifications, standards, drawings, and publications required by suppliers in connection with specific procurement functions, should be obtained from
5、the procuring activity or as directed by the contracting officer.) 3. REQUIREMENTS 3.1 First Article. * 3.1,l Preproduction sample. Unless otherwise specified (see 6.2) the contractor shall furnish a preproduction- sample for inspection in accordance with 4.3.1. the same procedures, materials, and p
6、lant facilities scheduled to produce the filters fulfilling the terms of the contract. items prior to procuring activity approval of the preproduction sample shall be at the contractors risk. Preproduction filters shall become property of the procuring activity and shall not be included in the quant
7、ity of filters called for in the contract or order. Preproduction sample filters shall be manufactured using Further production of * 3.2 Material. The filters shall consist of a sheet of polarizing material bonded between two homogeneous plates oQ stable, non-hy rosco Ic Grade Cy is satisfactory pro
8、vided the other requirements of this specification are met. substantially colorless glass. Glass meeting the requirements o B8 MIL- -1j4, * 3.2.1 Bonding adhesive. Unless otherwise specified in the contract or order (see 6.2), optical cement shall be in accordance with MIL-A-3920. 3.3 Shape and dime
9、nsions, The shape and dimensions of the filters shall be as specified on the applicable drawings. (See 6.2) 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.4 Transmittance and polarizing performance. The transmittance and polarizing performance o
10、f the filters shall be such that the following 1uminQus transmittance values will be met: Single filters Not less than 30 percent Two like filters Not less than 18 percent Not over 0.05 percent with axes parallel with axes perpendicular Two like filters . -. 3.5 Uniformity of transmittance and degre
11、e of polarization. The transmittance and degree of polarization of a pair of filters shall be uniform aver the entire area with the axes crossed or partially crossed. 3.6 Image clarity. The image definition of a target seen througha pair of filters shall not materially deteriorate as extinction is a
12、pproached, nor shall any diffused or scattered light he visible, * 3.7 Optical quality. 3.7.1 Surface and internal defects. Requirements related to surface and internal defects for each filter shall be in accordance with MIL-0-13830 with the appropriate “scratch and dig“ designation specified on app
13、licable drawings. 3.7.2 Surface accuracy. Fabrication tolerances for spherical power and irregularity of each surface of each filter shall be sufficient for each filter to meet the resolution requirements below.,_ 3.7.3 Resolution. The limit of resolution of each filter shall not exceed that Specifi
14、ed on the applicable drawings when each filter is tested as described in 4.6.6. 3.7.4 Deviation. The deviation at normal incidence shall not exceed that specified on applicable drawings. 3.8 Edges-. Filters shall be entirely free from edge separation when examined with the unaided eye. smooth ground
15、 to conform to the requirements of the applicable drawing. The periphery of each filter shall be 3.9 Temperature stability. Filters shall be capable of withstanding the temperature test specified in 4.6.1 without displaying discoloration, bubbles, or separation. 3.10 Weathering stability. Filters sh
16、all be capable of withstanding the weathering test specified in 4.6.2 without displaying discoloration, bubbles, or separation extending in from the edge more than two millimetres. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-F-21424A 32 m 7
17、Ob 0303346 3 m- MIL-F-21424A (OS ) Following the test, a pair of weathered filters shall be capable of meeting the requirements for uniformity of transmittance and degree of polarization specified in 3.5 and the luminous transmittance at extinction shall be not more than 0.3 percent. 3.11 Marking. T
18、he filter shall be scribed with the short, permanent lines to indicate, within one degree, the diameter that is vertical when the filter is oriented to reduce to a minimum the intensity of the light reflected from a horizontal specular surface at the polarizing angle. These scribed lines shall exten
19、d in from the edge of the filter two millimetres or less. On unbeveled filters the marking shall be provided on the side facing the polarized light when the requirements relative to depolarizing and birefringent inclusions are met. they shall be provided on the unbeveled side. On beveled filters 3.1
20、2 Workmanship. Workmanship shall be of such quality as to assure conformance with all requirements of the applicable drawings and of this specification. 4. QUALITY ASSURANCE PROVISIONS * 4.1 Responsibility for inspection. Unless otherwise specified in the contract or purchase order, the supplier is
21、responsible for the performance of all inspection requirements as specified herein. Except as otherwise specified in the contract or order, the supplier may use his own or any other facilities suitable for the performance of the inspection requirements specified herein, unless disapproved by the Gov
22、ernment. The Government reserves the right .to perform any of the inspections set forth in the specification where such inspections are deemed necessary to assure supplies and services conform to prescribed requirements. * 4.2 Classification of inspections. The inspection requirements specified here
23、in are classified as follows: 1. First Article Inspection (see 4.3) 2. Quality Conformance Inspection (see 4.4) 4.3 First Article Inspection. * 4.3 .l Preproduction inspection. Three preproduction sample filters of each size being purchased shall be submitted for inspection at an activity designated
24、 in the contract or order (see 6.2) to determine that the suppliers production methods are capable of yielding items that comply with the technical requirements of this specification. inspection shall consist of the examinations in 4.5 and all tests in 4.6. Failure of any filter to pass the inspecti
25、ons or one or more tests shall be cause for rejection of the preproduction sample. Preproduction 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-F-21424A 12 777770b 0303347 3 m * 4.4 Quality conformance inspection. The quality conformance inspe
26、ction shall consist of the examinations in 4.5 and all tests in 4.6. 4.4.1 Lot. For sampling purposes a lot shall consist of not more than 100 filters of the same size made from one pressing or batch as applicable. - * 4.4.2 Sampling. Unless otherwise specified the sampling plans and procedures shal
27、l be in accordance with ML-STD-105, Special Inspection level S-3, for temperature and weather stability tests (4.6.1 and 4.6.2), and General Inspection level II for all other tests and examinations. The classification of defects and acceptable quality levels (AQLs) shall be specified by the procurin
28、g activity (see 6.2). 4.5 Inspections, 4.5.1 Visual and dimensional examination. Filters shall be visually and dimensionally examined for completeness of manufacture, freedom from defects other than optical quality defects, proper item identification, conformance to applicable drawings and specifica
29、tions, and workmanship, 4.5.2 Cleaning, wrapping, packaging, packing, and marking examination. Sample filter containers shall be examined to determine whether or not cleaning, wrapping, packaging,.packing, and marking are in accordance with Section 5. 4.6 Test methods. * 4.6.1 Temperature stability.
30、 Expose the filters to -29 tr 3C- (-20 k 5F) for at least sixteen hours. After permitting them to return to room temperature, expose them to 68.5 rt 3C (155 rt 5F) for at least five hours. for discoloration, bubbles, and separation. After they have returned to room temperature, examine them * 4.6.2
31、Weathering stability. Measure transmittance and polarizing performance and uniformity of performance. Expose the filters to accel- erated weathering in accordance with method 6022 of FED-STD-406. Test specimens shall consist of entire filters, erated weathering may be permitted subject to the approv
32、al of the procuring activity. Upon completion of the test, examine the filters for discoloration, bubbles, and separation. Recheck uniformity of transmittance and degree of polarization and measure luminous transmittance at extinction. Other means of accel- 4.6.3 Transmittance and polarizing perform
33、ance. Filters shall be tested for transmittance and polarizing performance to determine compliance to 3.4 The equipment for luminous transmittance measurements shall include a non-polarizing light source of at least 150 watts, such as a projection lamp or other type of incandescent source having an
34、equivalent 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-F-EL2A 12 W 7799706 0303347 7 W MIL-P-21424A( OS) * d. Deviation. Filters shall be test
35、ed for deviation by means of a goniometer, spectrometer or other standard measuring instruments of adequate accuracy and sensitivity. 5. - PREPARATION FOR DELIVERY * 5.1 Cleaning, wrapping, and packaging. Filters shall be cleaned, Unit bags for level A wrapped, and packaged in accordance with MIL-P-
36、16898, level A or C as specified in the contract or order (see 6.2). packaging shall be constructed from material conforming to MIL-B-131, class 1. * 5.2 Packing. Filters shall be packed in accordance with MIL-P-16898, level A or C as specified in the contract or order (see 6.2). * 5.3 Identificatio
37、n marking. Filter containers shall be identified by the title, number, date of this specification, and by drawing number. 5.4 Other markings. In addition to any special marking required by the contract or order (see 6.2), shipping containers shall be marked in accordance with MIL-STD-129. 6. NOTES *
38、 6.1 Intended use. Optical polarizing filters may be used singly, in an optical instrument or with the unaided eye, to reduce the intensity of light reflected-from a specular surface or due to haze. also be used in pairs as a light attenuator (variable-density filter) by rotating one filter with res
39、pect to the other so that the light intensity may be varied from maximum to virtual extinction. They may 6.2 Ordering data. Procurement documents should specify the following: a. b. * C. Ji d. e. g* h. i. fi f. j. Title, number, and date of this specification. Drawing numbers of filters required. Wh
40、ether preproduction samples are required (see 3.1.1). Optical cement other than as specified (see 3.2.1). Testing activity for preproduction samples (see 4.3.1). Classification of defects and AQLs applicable (see 4.4.2) Levels of packaging and packing required (see 5.1, 5.2 and 6.3). Special marking
41、 when required (see 5.4). Number of unit packages per intermediate container. Number of.intermediate containers per pack, 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-F-21424A( OS) 6.3 Packaging and packing. Level Cy packaging and packing sh
42、all not be selected unless it is definitely known that the filters will be used immediately upon receipt. 6.4 Preproduction and production-control samples. Preproduction samples shall be cleaned, wrapped, and packaged in accordance with the requirements for Level C (see 5.1). The package shall be ad
43、dressed as directed by the procuring activity and shall be plainly marked as follows: Title, number , and date of this specification Drawing number Il Samples for preproduction tests“ Manufacturers name and code Manufacturers designation of the product Date of shipment Reference (authorizing or forw
44、arding letter) 6.5 Marginal identification. The margins of this specification c- are marked with an asterisk to indicate where changes (additions, modifications, corrections, deletions) from the previous issue were made. This was done as a convenience only and the Government assumes no liability wha
45、tsoever for any inaccuracies in these notations. are cautioned to evaluate the requirements of this document based on the entire content irrespective of the marginal notations and relationship to the last previous issue. Bidders and suppliers Custodian: Navy - OS * U. S. GOVERNMENT PRINTING OFFICE: 1975-M)3-766/0630 Preparing activity: Navy - OS Project Number 1240-N659 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
