1、= 3404583 0034b52 I EUROPEAN STANDARD EN 60735 NORME EUROPENNE EUROPISCHE NORM Supersedes HD 454 S1 : 1984 UDC 621.397.454 : 681.84.083.84 : 621.317.08 Descriptors: Video recording, magnetic recording, video recorder, magnetic tape, measurement method, mechanical propei-ties, electromagnetic propei-
2、ties, electrical properties English version Measuring methods for video tape properties (IEC 735 : 1991) Mthodes de mesure des proprits des bandes magntiques pour magntoscopes Video-Magnetbndern (CE1 735 : 1991) MeBverfahren fr die Eigenschaften von (IEC 735 : 1991) This European Standard was approv
3、ed by CENELEC on 1991-09-23. CENELEC members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up- to-date lists and bibliographical references concerning such nation
4、al standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official veisions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language
5、and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Noiway, Portugal, Spain, Sweden, Switze
6、rland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels O 1991 Copyright reserved to CENELEC members Ref. No. EN
7、 60735 : 1991 E Page 2 EN 60736 : 1991 Foreword The text of document 60B(C0)124, as prepared by Sub-committee BOB: Video recording, of IEC lkchnical Committee No 60: Recording, was submitted to the IEC-CENELEC parallel vote in January 1991. The reference document was approved by CENELEC as EN 60735
8、on 23 September 1991. This European Standard supersedes HD 454 S1 : 1984. The following dates were fixed: - latest date of publication of an identical national standard (dop) 1992-10-15 - latest date of withdraw1 of conflicting national standards (dow) 1992-10-15 For products which have complied wit
9、h HD 464 S1 : 1984 before 1992-10-15, as shown by the manufacturer or by a certification body, this previous standard may continue to apply for production until 1997-10-15. Annexes designated ?normative? are part of the body of the standard. In this standard, annex ZA is normative. W 3404583 0034b53
10、 3 W . m 3404583 O034654 5 m Page 3 EN 60735: 1991 CONTENTS Clause 1 scope 2 Normative references 3 Testing environment 4 Mechanical properties . . 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.1 1 Tape width . : Tape thickness Tensile tests . Residual elongation Longitudinal shrinkage . Coefficient of
11、 elongation in humidity Transverse cupping Longitudinal curvature Coefficient of friction . Layer-to-layer adhesion . Video head wear . 5 Electromagnetic and electrical properties 5.1 Coercivity Hc and retentivity Br 5.2 Coating resistance . 6 Tape properties measured on a video tape recorder 6.1 Vi
12、deo properties 6.2 Audio properties . ANNEX ZA (normative) . page 4 4 4 4 4 5 5 5 5 5 6 6 6 7 8 8 8 8 8 8 11 19 3404583 0034b55 i W Page 4 EN 60736 : 1991 MEASURING METHODS FOR VIDEO TAPE PROPERTIES i Scope This standard describes the measuring methods for evaluation of the properties of magnetic ta
13、pes used for video recorders. 2 Normative references The .following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and part
14、ies to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain regis- ters of currently valid International Standards. IEC 698: 1981, Measuring methods for tel
15、evision tape machines. IEC 883: 1987, Measuring method for chrominance signal-to-random noise ratio for video tape recorders. IEC 1 105: 1991, Reference tapes for video tape recorder systems (being printed). IS0 468: 1982, Surface roughness - Parameters, their values and general rules for speci- fyi
16、ng requirements. ISO/R 527: 1966, Plastics, Determination of tensile properties. CCI Recommendation 567-2 - Recommendations and repods of the CCI (7986) - Volume XII - Transmission of sound broadcasting and television signals over long dlstances (CMTT). 3 Testing environment All properties, if not o
17、therwise specified, shall be measured at a temperature of 20 OC f 1 OC at a humidity of 48 ?O to 52 Yo and an atmospheric pressure between 86 kPa and 106 kPa. The test sample to be measured shall be stored for 24 h in the above conditions to ensure correct testing results. This is defined as the sta
18、ndard environment for this standard. 4 Mechanical properties 4.1 Tape width The tape, covered with a glass plate, shall be measured without tension at a minimum of five different positions along the tape using a calibrated microscope or profile projector having an accuracy better than 2 pm. The tape
19、 width shall be defined as the average of the five readings. Page 5 EN 60735 : 1991 4.2 Tape thickness The tape thickness shall be obtained by using five samples from the beginning and five from the end of the tape, placing these ten sections on top of each other in a suitable manner, measuring with
20、 a micrometer gauge and dividing the reading by ten. 4.3 Tensile tests The measurements are made in accordance with ISO/R 527. The length of the test sample shall be 200 mm. The rate of elongation for all tensile tests shall be 100 mm/min (ISO/R 527, rate D). 4.3.1 Breaking strength The sample shall
21、 be loaded until the breaking point of the sample shall be reached. The force at that point shall be defined as the breaking strength of the tape. 4.3.2 Yield strength (F 5 %) The yield strength (F 5 Yo) shall be defined as the force necessary to produce 5 % elonga- tion of the tape. 4.4 Residual el
22、ongation To measure the residual elongation, a test sample of approximately 1 m shall be subjected to a tension of 50 N/mm2 total cross-section for a period of 3 min. The sample shall then be measured with negligible force (0,25 N) 3 min after the load has been removed. The residual elongation shall
23、 be stated as a percentage of the original tape length. 4.5 Longitudinal shrinkage A test sample (approximately 1 m) shall be stored in the standard environment for 48 h. It shall then be vertically suspended and loaded with 0,25 N. The length of the test sample, 3 min after the load has been applie
24、d, shall be defined as the original tape length. The environment shall be then changed to 50 OC and 13 YO relative humidity for a period of 18 h. Three hours after restoring the standard environment, the shrinkage of the sample shall be measured and expressed as a percentage of the original tape len
25、gth. 4.6 A test sample (approximately 1 m) shall be stored in the standard environment for 48 h. It shall then be vertically suspended and loaded with 0,25 N. The length of the test sample, 3 min after the toad has been applied, shall be defined as the original tape length. Coefficient of elongation
26、 in humidity W 3404583 0034657 O Page 6 EN 60735 : 1991 After increasing the relative humidity by 30 % for a period of 18 h the elongation shall be measured and expressed as a percentage of the original tape length. 4.7 Transverse cupping A tape sample of 10 mm length shall be placed, concave side d
27、own, on a smooth flat surface. Transverse cupping shall be the maximum departure of the tape sample from the flat surface. The time between cutting the tape and the measurement shall be at least 1 h. The tape sample and the test surface shall not be charged electrostatically. 4.8 Longitudinal curvat
28、ure 4.8.1 Static longitudinal curvature A tape sample of 1 m shall be allowed to unroll and assume its natural curvature on a flat surface. The maximum deviation of the edge of the tape from a straight line joining the extremities of the tape sample shall be defined as the static longitudinal curvat
29、ure. 4.8.2 Dynamic measuring of longitudinal curvature The test sample shall be measured in a test arrangement according to figures la and lb. The variation of the tape edge shall be measured with a light sensor through a slot of 1 mm width, In the area of the lower tape edge. The outpout signal sha
30、ll be proportional to the variations of the tape edge. The variation of each edge shall be measured and the worst value shall be reported. 4.9 Coefficient of friction 4.9.1 Quasi-static friction of the coating side A test drum shall be used, this being a stainless steel cylinder (figure 2) with a di
31、ameter of 100 mm and a surface roughness Ra = 0,25 pm in accordance with IS0 468. For particular applications, a drum of different material and different surface roughness may be used. The drum shall be cleaned with a solvent which leaves no residuals on the surface before starting the procedure. Pr
32、ocedure: with a velocity of 5 cm/min the test sample with its coating side facing the test drum shall be pulled over the drum for 2 min. After a short pause the procedure can be started under the same conditions and the results recorded. 1 F* a Fl Coefficient of friction p = - x In - where: a Fi = 0
33、,5 N load F2 = Fi + friction. (Values of velocity and load are chosen for practical reasons). Is the angle of wrap around the drum (n) in radians m 3404583 0034b58 2 m Page 7 EN 60735 : 1991 4.9.2 Quasi-static friction of the reverse side The drum shall be replaced by a stainless steel pin of 8 mm d
34、iameter and a surface roughness Ra I 0,07 pm. For particular applications, a pin of different material and different surface roughness may be used. The test procedure is as detailed in 4.9.1 except that the reverse side of the tape is facing the pin surface. 4.9.3 Dynamic friction of the coating sid
35、e The dynamic friction shall be measured with the equipment shown in figure 3. This machine is capable of varying the speed in the range from 0.5 cm/s to about 20 cm/s. For material of drum and pin, see 4.9.1 and 4.9.2. When a tape is run from 0,5 cm/s to about 20 cmls, the maximum value of p and th
36、e speed at which the maximum value is obtained shall be noted. From the friction versus speed curve, the coefficient of friction shall be calculated at two speed values, namely at the speed at which F2 is at a maximum and at a specified speed, characteristic for the recording equipment. The friction
37、al characteristics can be expressed by various values: a) maximum value of friction and its speed; b) at a certain speed to be specified. 4.9.4 Dynamic friction of the reverse side For measurement on the reverse side, the test procedure is the same as in 4.9.3, except that the reverse side is facing
38、 the pin. 4.1 O Layer-to-/ayer adhesion A tape of 1 m in length shall be wound on a glass tube of 36 mm diameter at a tension of 5 Nimm2 with one end of the tape fixed to the glass tube. The wound test piece shall be kept at a temperature of 45 OC f 3 OC and relative humidity of 80 % for 4 h, and af
39、terwards under the standard environment for 24 h. For some special applications requiring more stringent test conditions, the tape sample is wound on a 12,7 mm diameter tube of non-oxidizing material and exposed to a temperature of 54 OC and relative humidity of 84 % for 16 h and afterwards to the s
40、tandard environment for 24 h. Finally, the test piece shall be unwound slowly with a 0,l N load at the end. Then any tendency of tape sticking and delamination of magnetic coating shall be observed. I 3404583 0034659 4 W Page 8 EN 60735 : 1991 4.1 1 Video head wear Tape tension, head mounting, pole
41、tip protrusion and all other machine parameters shall be controlled in accordance with the specification of the recorder used. Before starting the test, one reel of the tape type to be tested shall be run for full contouring of the heads. Another reel of the same tape type shall be run for 100 passe
42、s of at least 45 min each pass and the decrease of head protrusion shall be measured by means of a suitable instrument. The decrease of head protrusion is a measure of head wear. The playing time of the test piece, the type of heads, and the head status shall be stated. 5 Electromagnetic and electrl
43、cal properties 5.1 Coercivity and retentivity are measured by using a dynamic B-H versus tracer. The frequency and the field strength used shall be stated. 5.2 Coating resistance Coercivity Hc and retentivity Br I hysteresis loop Two electrodes shall be set up at a distance apart corresponding to th
44、e sample width as shown in figure 4. The cross-section of the electrodes shall be one-quarter of a circle of 1 cm in radius. The test sample shall be placed across the electrodes, with the longitudinal direction of the tape being perpendicular to the electrodes and with the side of the tape under te
45、st being in contact with the electrodes. Next, two weights producing a tension of 5 N/mm* shall be hung at the two ends of the test sample. Then, the electrical resistance between the two electrodes shall be measured by a suitable instrument. The coating resistance is defined as that electrical resi
46、stance. 6 Tape properties measured on a video tape recorder The type of system and machine shall be stated and used in accordance with the specifications of the manufacturers instruction manual. The test results shall be related to the respective reference tape if available and where appropriate. Re
47、ference tapes are listed in IEC 1105 or in the corresponding IEC VTR standard. 6.1 Video properties 6.1 .I Writing current for maximum r.f. output During recording of a 100 % white level video signal the record current shall be varied. After switching over to playback, the r.f. output representing t
48、he 100 % white level shall be measured in the FM channel, ahead of any AGC or limiting. The record current giving the maximum output is called the record current for maximum r.f. output. = 3404583 0034bb0 O =, Page 9 EN 60738 : 1991 6.1.2 R. F. output - luminance The r.f. output is the maximum r.f.
49、level obtained at the writing current as described in 6.1.1. 6.1.3 For colour under recording systems, the composite signal with the luminance r.f. and the chrominance r.f ., where respective recording levels depend on the system specification, shall be recorded on the tape. Then, the chrominance r.f. output shall be separately measured ahead of any AOC or limiting. R. F. output - chrominance 6.1.4 Video signal-to-noise ratio 6.1.4.1 Wideband video signal-to-noise ratio This method is based upon IEC 698. sign. P. 0 P. Wideband video S/N = 20 log VnOise r.m.s. Where Vslgn
