1、I INCH-POUND I MIL-PRF-49148D (CR) 4 March 1999 SUPERSEDING 26 May 1992 MIL-L-49148C (CR) PERFORMANCE SPECIFICATION LENS ASSEMBLY, OBJECTIVE VIEWER, DRIVERS NIGHT VISION, AN/WS-2 (V) This specification is approved for use by US Army Communications-Electronics Command, Department of the Army, and is
2、available for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers the Objective Lens Assembly, herein known as objective lens, which is part of Viewer, Drivers Night Vision, AN/WS-2 (V) . 2. APPLICABLE DOCUMENTS 2.1 General. The documents l
3、isted in this section are specified in sections 3 and 4 of this specification. This section does not include documents in other sections of this specifications or recommended for additional information or as examples. While every effort has been made to insure the completeness of this list, document
4、 users are cautioned that they must meet all specified requirements in sections 3 and 4 of this specification, whether or not they are listed. Beneficial comments (recommendation, additions, deletions) and any pertiner data which may be of use in improving this document should be addressed to: HQ, U
5、SA Communications-Electronics Command ATTN: AMSEL-LC-LEO-E-EP, Fort Monmouth, NJ 07703-5023 by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. AMSC N/A FSC 5855 DISTRIBUTION STATEMENT A: Approved for public release; distribut
6、ion is unlimited. Licensed by Information Handling ServicesMIL-PRF-49148D (CR) 2.1.1 Reference documents, drawings and publications. The following other Government documents, drawings and publications form a part of this document to the extent specified herein. Unless otherwise specified, the issues
7、 are those cited in the solicitation (see 6.2.f). DRAWINGS USA COMMUNICATIONS-ELECTRONICS COMMAND SM-D-771334 - Barrel Assembly, Lens, Objective (Copies of Specifications, standards, drawings, and publications required by contractors in connection with specific procurement functions should be obtain
8、ed from the procuring activity or as directed by the contracting officer.) 2.2 Order of precedence. In the event of a conflict between the text of this specification and the references cited herein, the text of this specification takes precedence. Nothing in this specification, however, supersedes a
9、pplicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Description. The objective lens assembly is mounted to and is part of the Viewer, Drivers Night Vision AN/WS-2(V). 3.2 Construction. The objective lens assembly shall be constructed to assure compliance
10、 with the contract configuration baseline and in accordance with SM-D-771334 as applicable. 3.3. First article test (FAT). When specified in the contract (see 6.2.e and 6.2.h) the contractor shall furnish units for FAT inspection and approval (see 4.2). 3.4 Materials. The contractor shall select par
11、ts and materials that are fully capable of meeting all operational and environmental requirements specified herein. The materials specified in the applicable drawings are recommended, but not mandatory. Selection criteria of the class, grade or type part shall ensure the material will be able to per
12、form its intended function when it is assembled. Verification of the supplier meeting the overall performance requirements shall be the governing acceptance standard. Recovered materials shall be used to the maximum extent possible. 3.5 Performance characteristics. 3.5.1 Effective focal length. The
13、objective lens shall have an Effective Focal Length (EFL) of 33.6, I 0.5 millimeters (mm) . 3.5.2 Field of view. The field of view shall be not less than 44 degrees for a 25mm diameter format. 2 Licensed by Information Handling ServicesMIL-PRF-49148D (CR) 3.5.3 Linear distortion. The objective lens
14、shall have between 9 percent and 12 percent barrel distortion. 3.5.4 Modulation Transfer Function (MTF) on axis. The MTF shall be not less than the values specified in Table I when tested on axis with a sine wave pattern setup that utilizes an S-20-ER response photomultiplier and a tungsten illumina
15、tion source operated at 2854K k200K color temperature. The test shall be repeated with the objective rotated 90 degrees about the optical axis. I Test Frequency I (cycles/millimeter) I on the Image Intensifier I I I I I I I I I Modulation Transfer I I (Percent) I I I I I I 10 I 20 I 30 I 40 84 70 55
16、 40 3.5.5 T-number. The T-number shall be no greater than 1.25 when tested using a light source operated at 2854K k200K color temperature and a photo- detector with an S-20ER response. 3.5.6 Veiling glare. The veiling glare (stray light) shall be no greater than 2.5 percent when using a photodetecto
17、r with an S-20ER response. 3.5.7 Flange focal length. The flange focal length shall be not less than 0.039 inches (0.991mm) when measured from the outermost flange surface of the 1.5-inch diameter central area of the lens retainer. 3.6 Environmental. Verification of conformance after environmental t
18、ests shall be Modulation transfer function (3.5.4), Veiling glare (3.5.6) and Flange focal length (3.5.7) . 3.6.1 Temperature Extremes. The objective lens shall not be damaged nor suffer degradation of performance (see 3.10.1 and 3.10.4) after being subjected to storage at +68C to -51C. The objectiv
19、e lens shall not be damaged nor suffer degradation of performance (see 3.10.1 and 3.10.4) after being subjected to repetitive temperature changes between +23C and +68C in 5 minutes and between +23C and -51C in 5 minutes. Soak time at each temperature extreme shall be sufficient for the objective len
20、s to attain temperature stabilization. Time for temperature stabilization is defined as the amount of time required for the most internal part of the unit under test to achieve the specified temperature. 3 Licensed by Information Handling ServicesMIL-PRF-49148D (CR) 3.6.2 Vibration. The objective le
21、ns shall not be damaged nor suffer degradation of performance (see 3.10.1 and 3.10.4) after being subjected to vibration equivalent to that encountered in tracked vehicles during 5000 miles of operation. Vibration shall be limited to one sine sweep from 5.0 to 500 Hertz (Hz) and back to 5.0 Hz withi
22、n 15 minutes in the vertical axis only. Vibration shall be performed from 5.0 to 5.5 Hz. at 1-inch displacement, 5.5 to 30 Hz. at 1.5 gs peak, 30 to 50 Hz at 0.33-inch displacement and 50 to 500 Hz. at 4.2 gs peak. 3.6.3 Shock. 3.6.3.1 Basic shock. The objective lens shall not be damaged nor suffer
23、degradation of performance (see 3.10.1 and 3.10.4) after being subjected to basic shock of 40 gs (see 3.10.5) at 18 milliseconds. 3.6.3.2 Weapon shock. The objective lens shall not be damaged nor suffer degradation of performance (see 3.10.1 and 3.10.4) after being subjected to simulated weapon firi
24、ng shock of 100 gs at 1.5 milliseconds one half sine pulse. 3.6.4 Immersion. The objective lens shall not be damaged (see 3.10.1) after being immersed in fresh water to a depth of not less than 3 feet for a period of not less than 30 minutes. The objective lens shall be pre- conditioned by exposure
25、to temperature of +45OC I3OC for a period of 2 hours prior to being immersed in the fresh water at a temperature of +18OC I5OC. 3.7 Treatment and painting. Treatment and painting shall be anti- reflective, shall be rust resistant and as specified on applicable drawings unless otherwise specified in
26、the contract or purchase order. 3.8 Marking. Marking shall be in accordance with applicable drawings unless otherwise specified in the contract or purchase order. 3.9 Workmanship. Standards of workmanship shall be such that the objective lens will meet all requirements of this specification and any
27、referenced specifications or drawings. 3.10 Technical interpretations. The following technical interpretations are, when referenced in sections 3 or 4, mandatory for this specification. 3.10.1 Damage. Damage is defined as any breakage, loosening, shift, dents, failure of any finish, hardware, connec
28、tion, or component, or condensation, fogging or moisture on any internal surface. 3.10.2 Ambient temperature. Ambient temperature is defined as +23OC, I looc. 3.10.3 Environmental temperature. Environmental chamber temperature shall be controlled to within I5OC of the specified temperature unless ot
29、herwise specified. 4 Licensed by Information Handling ServicesMIL-PRF-49148D (CR) Inspection Effective focal length Field of view Linear distortion Modulation transfer function T-number Veiling glare Flange focal length 3.10.4 Degradation of performance. Any deterioration in quality, or failure to o
30、perate with the requirements of this specification. Requirement Paragraph 3.5.1 3.5.2 3.5.3 3.5.4 3.5.5 3.5.6 3.5.7 3.10.5 iig“. iig“ is defined as an acceleration or deceleration of 32.17 feet per secondper second. Inspection Temperature Extremes Vibration Shock Immer s i on 4. VERIFICATION Require
31、ment Paragraph 3.6.1 3.6.2 3.6.3 3.6.4 4.1 Classification of inspections. Inspections shall be classified as follows : a. First article tests (4.2) b. Conformance inspection (4.3) 4.2 First Article Test (FAT). When specified in the contract or purchase order (see 6.2.h), first article testing shall
32、be performed by the contractor. The quantity of first article test samples shall be as specified in the contract or purchase order(see 6.2.e) and shall be selected from the first production lot. 4.2.1 FAT Tests. Each objective lens in the first production lot shall be subjected to the performance te
33、sts of Table II. After completion of this test, objective lens assemblies selected as samples for FAT testing shall be subjected to the tests of Table III which may be performed in any order except that Immersion shall be performed last. Failure of any test shall be cause for rejection of that objec
34、tive lens and may be cause for rejection of the FAT. TABLE II. Unit first article testincr. Table III Sample first article testing 4.2.1 Disposition of FAT samples. Disposition of FAT samples shall be as specified in the contract or purchase order (see 6.2.e). 4.3 Conformance inspection. Requirement
35、s for conformance inspection shall be as specified in the contract or purchase order (see 6.2.9). Unless otherwise specified, all tests shall be performed at ambient temperature (see 3.10.2). 5 Licensed by Information Handling ServicesMIL-PRF-49148D (CR) 5. PACKAGING 5.1 Packaging. For acquisition p
36、urposes, the packaging requirements shall be as specified in the contract or purchase order (see 6.2.c). When packaging is to be performed by DoD personnel, these personnel need to contract the responsible packaging activity to ascertain requisite packaging requirements. Packaging requirements are m
37、aintained by the Inventory Control Points packaging activity within the Military Department of Defense Agency, or within the Military Departments System Command. Packaging data retrieval is available from the managing Military Departments or Defense Agencys automated packaging files, CD-ROM products
38、, or by contacting the responsible packaging activity. 6. NOTES (This section contains information of a general or explanatory nature that may be helpful, but is not mandatory.) 6.1 Intended use. The objective lens is used with the AN/WS-2 (V) for driver viewing during periods of darkness. 6.2 Acqui
39、sition requirements. Acquisition documents must specify the following: a. b. C. d. e. f. h. Title, number, and date of this specification. Necessary actions by contractor in the event of a lot failure (see 4.2.1). Packaging requirements. Sampling plans for lot testing. Quantity and schedule for FAT
40、for all line items and disposition of FAT samples. Issue of DODISS to be cited in the solicitation, and if required, the specific issue of individual documents referenced (see 2.1 and 2.1.1). Statement identifying that the contractor must submit his proposal for conformance inspection to include spe
41、cific requirements to be verified and the sampling plan to be used to provide the desired confidence level. Statement specifying that FAT testing is, or is not, required. 6.3 Definitions. See 3.10. 6 Licensed by Information Handling ServicesMIL-PRF-49148D (CR) 6.4 Subject term keyword listing. None
42、Effective focal length Field of view Linear distortion Modulation transfer function T-number Veiling glare 6.5 Changes from previous issue. Marginal notations are not used in this revision to identify changes with respect to the previous issue due to the extensive changes. Custodian: Army - CR Preparing Activity Army - CR Project 5855-0098 7 Licensed by Information Handling Services
