MIL-P-12706 Periscope, M15

Pages 1 - 2 - 3 - 4 - 5 - 6

No. 51-72-71

26 January 1949

Superceding

Frankford Arsenal Tentative

FXS 968

10 December 1948

U. S. ARMY SPECIFICATION

PERISCOPE, M15

SCOPE AND CLASSIFICATION.

1.1 This specification covers one type of instrument known as Periscope,

M15.

2. APPLICABLE DRAWINGS AND SPECIFICATIONS.

2.1 Ordnance Department drawing Class 22, Division 425, DRAWING 1, titled,

Periscope, M15, List of Drawing, lists or indicates all drawings and speci-

fications which form part of this specification.

2.2 All drawings and specifications shall be of the issue in effect on

date of invitation for bids. The issue in effect shall be that issue which

the contracting officer shall designate or furnish the bidder.

3. REQUIREMENTS.

3.1 Material shall be in accordance with the drarings, general specif-

ications, and material specifications forming part of this specification.

3.2 Workmanship shall be in accordance with U. S. Army Specification

No. 51-7 Instruments, Fire Control; General Specification Governing the Manu-

facture and Inspection of; and U. S. Army Specification No. 51-70-2 Optical

Components for Fire Control Instruments; General Specification Governing the

Manufacture, Assembly and Inspection of.

3.3 General Requirements and associated tests common to all optical fire

control instruments are contained in U. S. Army Specifications No. 51-7 and

51-70-2 and are mandatory in so far as they are Applicable.

3.4 Image, Quality."

3.4.1 Seven power system.- The images shall be practically free from

distortion, astigmatism, curvature of field, coma, and chromatic and serial

aberrations for a radial distance of 2 degrees 30 minutes from the center of

the field of view. Images showing my of the above defects in the area speci-

fied above shall be cause for rejection of the periscope, if judged objection-

able by the inspector.

3.4.1.1 Astimagism at the center of the field shall not exceed 0.25

diopter.