1、SMPTE 2bfl 95 8357401 0003883 799 mi SMPTE STANDARD ANIil/SMPTE 26M-1995 Revision of ANSIISMPTE 26M-1989 for Video Recording - 1 -in Helical-Scan Recorders - Raw Stock for Reference Tapes 1 Scope This standard specifies dimensions for the width, thickness, and width deviation of raw tape stock used
2、to record reference tapes for 1 -in helical-scan video tape recorders. Conditions before testing and testing environment are also specified. Page 1 of 2 pages 4 Dimensions 4.1 Tape stock The dimensions of the tape stock for recording refer- ence tapes shall be as specified below: Dimensions Millimet
3、ers 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this standard are
4、 encouraged to investigate the possibility of applying the most recent edition of the standard indicated below: ANSI/ASTM D638M-91, Test Method for Tensile Properties of Plastics Width: 25.350 * 0.025 Thickness: 0.027 to 0.030 Maximum rate of width change: less than 0.01 5 over alength of 250 4.2 Lo
5、ngitudinal dimensional change The longitudinal dimensional change of the raw tape stock kept under the following conditions for 48 hours shall be less than 0.03%). Temperature: 45C I 1C Relative humidity: (85 I 2)% Tape tension: 2.0 N I 0.5 N 3 Conditioning for testing and recording 4.3 Modulus of e
6、lasticity 3.1 Tests, measurements, and recordings made on the raw tape stock to check the requirements of this standard shall be made under the follow- ing conditions: Temperature: 23C 1C Relative humidity: (50 I 2)% Barometric pressure: 86 kPa to 1 O6 kPa 3.2 The raw tape stock shall be stabilized
7、at the above conditions for 24 hours, rewound on a reel at a tape tension of 2.0 N I 0.5 N, and kept at the same conditions for another 24 hours. The longitudinal modulus of elasticity shall be measured in accordance with ANSI/ASTM D638M-91, and shall nieet the following specifica- tions: N/rnrn2 Ib
8、/in2 Minimum 2.9 x 1 O3 0.43 x 1 O6 Maximum 7.4 io3 1 .o7 lo6 4.4 Poissons ratio Poissons ratio shall be 0.4 nominal. CAUTION NOTICE This Standard may be revised or withdrawn at any time. The procedures of the Standard Developer reqiiire that action be taken to reanirm, revise, or withdraw this stan
9、dard no later than five years from the date of publication Purchasers of standards may receive current information on all standards by calling or writing the Standard Developer Copyright O 1995 by THE SOCIETY OF - American National Standard MOTION PICTURE AND TELEVISION ENGINEERS 595 W Hartsdale Ave
10、, White Plains, NY 10607 (914) 761-1100 Approved February 13, 1995 ANSVSMPTE 26M-1995 - SMPTE 2bM 95 8357401 0001884 b25 M NOTE - In addition to the parameters specified in this standard, there are other parameters such as coating and frictional characteristics that affect the operation of thetape. Manufacturersof referencetapeshould take thesfparametersintoconsideration. Page 2 of 2 pages
