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1、INTERNATIONAL STANDARD ISO/IEC 13421 First edition 1993-l 2-l 5 Information technology - Data interchange on 12,7 mm, 48-track magnetic tape cartridges - DLT 1 format Technologies de /information - ichange de don - length: 102 mm. Attach a mass of 1 000 g to the opposite end of the tape. Attach, 25,
2、4 mm above the mass, a narrow strip of double-sided adhesive tape to the magnetic coating. Slowly rotate the cylinder, so that the tape winds uniformly around it into a compact and even roll. The double-sided tape secures the end and prevents unwinding when the mass is removed. The cylinder with the
3、 tape shall then be exposed to the temperature and humidity cycle given in table 1. Table 1 - Temperature and humidity cycle Time Temperature 16hto18h 54 “C 4h 54 “C 1 hto2h 21 “C RH 85 % 10 % or less 45 % Open the end of the roll and remove the double-sided adhesive tape. Release the free end of th
4、e tape. The outer one or two wraps shall spring loose without adhesion. Hold the free end of the tape and allow the cylinder to fall, thereby unwinding the tape. The tape shall show no coating delamination, except for the 5 1 mm of tape nearest to the cylinder. Copyright International Organization f
5、or Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/05/2007 01:10:51 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 13421:1993 (E) Figure 2 - Measurement of layer-to-layer adhesion 7.15 M
6、odulus of elasticity The modulus of elasticity (Youngs modulus) is the ratio of stress to strain in the longitudinal direction. 7.15.1 Requirement The modulus of elasticity shall be between 5 500 N/mm2 and 8 500 N/mm2. 7.15.2 Procedure Clamp a test piece of tape at least 178 mm in length with an ini
7、tial 102 mm separation between the jaws of a universal testing machine with a nominal crosshead speed of 3 mrn/min. Calculate the modulus using the chord of the curve between the force at 0 % and 1 % elongation. 7.16 Flexural rigidity Hexural rigidity is the ability of the tape to resist bending in
8、the longitudinal direction. 7.16.1 Requirement The flexural rigidity of the tape in the longitudinal direction shall be between 0,5 x lob3 N . mm and 2,9 x 10m3 N . mm. 7.16.2 Procedure Calculate the flexural rigidity D from the following equation: Copyright International Organization for Standardiz
9、ation Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/05/2007 01:10:51 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 13421:1993 (E) D-Ed3 - 12 x (l-v*) where E t V 7.17 = modulus of elasticity obtained
10、 from 7.14; = measured thickness of the tape in millimetres; = Poissons ratio, set to 0,33. Tensile yield force The tensile yield force required to elongate the test piece by 3 % shall not be less than 14,7 N. 7.17.1 Procedure Use a static-weighing-constant-rate-of-grip separation tester capable of
11、indicating the load with an accuracy of + 2 %. Clamp a test piece of tape at least 178 mm long with an initial 102 mm separation between the jaws. Elongate the test piece at a rate of 51 mrn/min. until a minimum elongation of 10 % is reached. The force required to produce an elongation of 3 % is the
12、 tensile yield force. 7.18 Electrical resistance 7.18.1 Requirement The electrical resistance of any square area of the magnetic coating shall be greater than 50 x lo6 52; - not exceed 50 x 1012 Q. The electrical resistance of any square area of the back coating shall - not exceed 100 x lo6 R. 7.18.
13、2 Procedure Condition a test piece of tape in the test environment for 24 h. Position the test piece over two 24-carat gold-plated (see figure 3), semi-circular electrodes having a radius r = 25,4 mm and a finish of at least N4, so that the recording surface is in contact with each electrode. These
14、electrodes shall be placed parallel to the ground and parallel to each other at a distance d = 12,7 mm between their centres. Apply a force F of 1,62 N to each end of the test piece. Apply a d.c. voltage of 100 V f 10 V across the electrodes and measure the resulting current flow. From this value, d
15、etermine the electrical resistance. Repeat for a total of five positions along the test piece and average the five resistance readings. For the back coating repeat the procedure with the back surface in contact with the electrodes. 10 Copyright International Organization for Standardization Provided
16、 by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/05/2007 01:10:51 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 13421:1993 (E) Figure 3 - Measurement of electrical resistance When mounting the test piece, make
17、sure that no conducting paths exist between the electrodes except that through the coating under test. NOTE 5 - Particular attention should be given to keeping the surfaces clean. 7.19 Inhibitor tape This International Standard does not specify parameters for assessing whether or not a tape is an in
18、hibitor tape. However, annex G gives further information on inhibitor tapes. 7.20 Abrasivity Tape abrasivity is the tendency of the magnetic coating to wear the magnetic heads. 7.20.1 Requirement The depth of the wear pattern in a ferrite wear bar shall be less than 1,27 l.trn. 7.20.2 Procedure A te
19、st piece 61 m in length shall be passed for 100 passes (50 cycles) over a rectangular bar of manganese zinc ferrite (see figure 4). The bar shall be 0,3 mm wide and its top surface shall be rounded off with a radius r. = 5 mm. The tape speed shall be 2,54 m/s, the tension shall be nominally 1,3 N an
20、d the wrap angle shall be 12”. The wear depth is measured with a profilometer across the width of the tape path. NOTE 6 - Manganese zinc ferrite should be available commercially from Philips Ceramic Division in Saugerties (NY) under order part number 3H7. This information is given for the convenienc
21、e of the users of this International Standard and does not constitute an endorsement by IS0 or IEC of this product. 11 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/05/2007 01:10
22、:51 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 13421:1993 (E) Figure 4 - Measurement of abrasivity (not to scale) 7.21 Light transmittance of the tape and the leader The light transmittance of the tape and the leader shall be less than 5 % when measured accordi
23、ng to the method specified in annex A. 7.22 Coeffkient of dynamic friction The coefficient of dynamic friction is measured between the surfaces of the tape, and calcium titanate ceramic. 7.22.1 Requirements Between the magnetic surface and the back surface : greater than 0,20 Between the magnetic su
24、rface and other surfaces: 0,lO to 0,40 Between the back surface and calcium titanate: 0,lO to 0,25 7.22.2 Procedure for the measurement of the friction between the magnetic surface and the back surface a) Wrap a first piece of tape around a calcium titanate ceramic cylinder (Ra = 0,05 pm) of diamete
25、r 25,4 mm and wrap it with a total wrap angle of more than 90” with the back surface outwards. b) Wrap a second test piece, with the magnetic surface inwards, around the first test piece with a total wrap angle of 90”. c) Exert on one end of the outer test piece a force of 0,54 N. d) Attach the othe
26、r end to a force gauge mounted on a linear slide. e) Drive the slide at a speed of 1 mm/s. f) Connect the force gauge to a plotter to record the results. 12 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, B
27、ernie Not for Resale, 04/05/2007 01:10:51 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 13421: 1993 (E) 7.22.3 Procedure for the measurement of the friction between the magnetic surface or the back surface and calcium titanate ceramic a Wrap a piece of tape around
28、 a calcium titanate ceramic cylinder (Ra = 0,05 pm) of diameter 25,4 mm and wrap it with a total wrap angle of 90” with the magnetic surface or the back surface, as appropriate, inwards. b) Exert on one end of the test piece a force of 0,54 N. c Attach the other end to a force gauge mounted on a lin
29、ear slide. 4 Drive the slide at a speed of 1 mm/s. e Connect the force gauge to a plotter to record the results. NOTE 7 - Calcium titanate ceramic should be available commercially from Philips Ceramic Division in Saugerties (NY) under order part Ca Ti. This information is given for the convenience o
30、f users of this International Standard and does not constitute an endorsement by IS0 or IEC of this product. 8 Magnetic recording characteristics The magnetic recording characteristics shall be defined by testing the requirements given below. When performing the tests, the output or resultant signal
31、 shall be measured on the same relative pass for both a tape calibrated to the Master Standard Reference Tape and the tape under test (read-while-write, or on equipment without read- while-write capability, on the first forward-read-pass) on the same equipment. The following conditions shall apply t
32、o the testing of all magnetic recording characteristics, unless otherwise noted. tape condition: a.c. erased to 2 % or less of the Average Signal Amplitude tape speed: 2,54 m/s read track: within the written track gap alignment: within 5 between the mean write transitions and the read gap write gap
33、length: 2,O w f 093 cun write gap width: 0,216 mm f 0,010 mm read gap length: 0,36 pm f 0,lO pm read gap width: 0,102 mm f 0,010 mm tape tension: 1,14 N f 0,14 N recording current: Test Recording Current physical recording densities: 2f= 1674 ftpmm f 33 ftpmm, corresponding to 2,126 MHz * 2 % lf= 83
34、7 ftpmm * 16 ftpmm, corresponding to 1,063 MHz * 2 % Bandwidth of the read amplifier: 3,2 MHz Typical Field The Typical Field shall be between 75 % and 125 % of the Reference Field. Traceability to the Reference Field is provided by the calibration factors supplied with each Secondary Standard Refer
35、ence Tape. 13 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/05/2007 01:10:51 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 13421:1993 (E) 8.2
36、Signal amplitude The Average Signal Amplitude shall be between 85 % and 115 % of the SRA. Traceability to the SRA is provided by the calibration factors supplied with each Secondary Standard Reference Tape. 8.3 Resolution The ratio of the average signal amplitude at the physical recording density of
37、 1 674 ftpmm to that at the physical recording density of 837 ftpmm shall be between 90 % and 120 % of the same ratio for the Master Standard Reference Tape. Traceability to the resolution of the Master Standard Reference Tape is provided by the calibration factors supplied with each Secondary Stand
38、ard Reference Tape. 8.4 Overwrite Overwrite is the ratio of the residual signal of the average signal amplitude recorded at 837 ftpmm after being overwritten at 1 674 ftpmm to the average signal amplitude of the 837 ftpmm signal. 8.4.1 Requirement The overwrite for the tape shall be less than 110 %
39、of the overwrite for the Master Standard Reference Tape. Traceability to the overwrite of the Master Standard Reference Tape is provided by the calibration factors supplied with each Secondary Standard Reference Tape. 8.5 Peak shift Peak shift is measured as the time displacement from nominal of the
40、 ONES transitions in the MFM-recorded pattern 1101101 lo 8.5.1 Requirement For a peak shift ratio of n % of the Master Standard Reference Tape, the measured peak shift ratio shall be between (n-2) % and (n+2) %. Traceability to the peak shift ratio of the Master Standard Reference Tape is provided b
41、y the calibration factors supplied with each Secondary Standard Reference Tape. 8.5.2 Procedure The time interval measurements shall be averaged over 250 ONE-ONE-ZERO patterns taken at a sampling rate of 96 times 7% The time between adjacent peaks in the ONE-ONE interval is denoted as tl. The time b
42、etween the last ONE in the ONE- ONE interval to the last ONE in the following ONE-ONE interval is denoted as to. Peak shift = 35 -to 2f x 100% 0 14 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not
43、 for Resale, 04/05/2007 01:10:51 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 13421:1993 (E) -.- t1 t0 Figure 5 - Measurement of peak shift 9 Tape quality 9.1 Missing pulses A missing pulse is a loss of read signal amplitude. A missing pulse exists when the base-
44、to-peak read signal amplitude is less than 35 % half of the Average Signal Amplitude for the preceding 25,4 mm of tape. 9.1.1 Requirement The average missing pulse rate shall be less than 20 missing pulses for any recorded length of track of 100 m. 9.2 Missing pulse zone A missing pulse zone is a se
45、quence of missing pulses exceeding 100 mm. 9.2.1 Requirement Missing pulse zones shall not occur. 9.3 Tape durability This International Standard does not specify parameters for assessing tape durability. However, a recommended procedure is described in annex H. Section 3 - Mechanical specifications
46、 of the tape cartridge 10 General The tape cartridge shall consist of the following elements - a case - a reel for the magnetic tape - a locking mechanism for the reel - a magnetic tape wound on the hub of the reel - a write-inhibit mechanism - a tape leader 15 Copyright International Organization f
47、or Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/05/2007 01:10:51 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO/IEC 13421:1993 (E) Dimensional characteristics are specified for those para
48、meters deemed mandatory for interchange and compatible use of the cartridge. Where there is freedom of design, only the functional characteristics of the elements described are indicated. Where they are purely descriptive the dimensions are referred to three reference planes A, B, and C forming a geometrical trihedral. Where the dimensions are related to the position of the cartridge in the drive, they may be referenced to another surface of the cartridge. In the enclosed drawings a typical implementation is represented in third angle pr