1、BRITISH STANDARD BSEN 60735:1992 Methods for Measurement of video tape properties The European Standard EN60735:1991 has the status of a British StandardBSEN60735:1992 This British Standard, having been prepared under the directionof the Electronic Equipment Standards Policy Committee, was published
2、 underthe authority of the Standards Board and comes intoeffect on 15 May1992 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference EEL/22 Draft for comment 89/29024 DC ISBN 0 580 20810 9 Cooperating organizations The European Committee for Electrotechnica
3、l Standardization (CENELEC), under whose supervision this European Standard was prepared, comprises the national committees of the following countries: Austria Italy Belgium Luxembourg Denmark Netherlands Finland Norway France Portugal Germany Spain Greece Sweden Iceland Switzerland Ireland United K
4、ingdom Amendments issued since publication Amd. No. Date CommentsBSEN60735:1992 BSI 10-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 Text of EN 60735 3 National annex NA (informative) Inside back cover National annex NB (informative) Inside back co
5、verBSEN60735:1992 ii BSI 10-1999 National foreword This British Standard has been prepared under the direction of the Electronic Equipment Standards Policy Committee and is the English language version of EN60735, “Measuring methods for video tape properties”, published by the European Committee for
6、 Electrotechnical Standardization (CENELEC). It was derived by CENELEC from IEC735:1991 published by the International Electrotechnical Commission (IEC). For ease of publication, some of the figures also include the French text. This British Standard supersedes BS6412:1983 which will be withdrawn on
7、15 October1992. Copies of CCIR documents may be purchased from BSI Sales, Linford Wood, Milton Keynes MK146LE. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a Britis
8、h Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to14, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have ha
9、d amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60735 UDC 621.397.454:681.84.083.84:621.317.08 Supersedes HD 454 S1:1984 Descriptors: Video recording, magnetic recording, video recorder, magnetic
10、tape, measurement method, mechanical properties, electromagnetic properties, electrical properties English version Measuring methods for video tape properties (IEC 735:1991) Mthodes de mesure des proprits des bandes magntiques pour magntoscopes (CEI 735:1991) Meverfahren fr die Eigenschaften von Vid
11、eo-Magnetbndern (IEC 735:1991) This European Standard was approved by CENELEC on1991-09-23. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-d
12、ate lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation unde
13、r the responsibility of a CENELEC member into its own language 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, L
14、uxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Bru
15、ssels 1991 Copyright reserved to CENELEC members Ref.No.EN60735:1991EEN60735:1991 BSI 10-1999 2 Foreword The text of document60B(CO)124, as prepared by Sub-committee60B: Video recording, of IEC Technical Committee No60: Recording, was submitted to the IEC-CENELEC parallel vote in January1991. The re
16、ference document was approved by CENELEC as EN60735 on23 September1991. This European Standard supersedes HD454S1:1984. The following dates were fixed: For products which have complied with HD454S1:1984 before1992-10-15, as shown by themanufacturer or by a certification body, this previous standard
17、may continue to apply for production until1997-10-15. Annexes designated “normative” are part of the body of the standard. In this standard, Annex ZA is normative. Contents Page Foreword 2 1 Scope 3 2 Normative references 3 3 Testing environment 3 4 Mechanical properties 3 4.1 Tape width 3 4.2 Tape
18、thickness 3 4.3 Tensile tests 3 4.4 Residual elongation 3 4.5 Longitudinal shrinkage 3 4.6 Coefficient of elongation in humidity 3 4.7 Transverse cupping 4 4.8 Longitudinal curvature 4 4.9 Coefficient of friction 4 4.10 Layer-to-layer adhesion 4 4.11 Video head wear 5 5 Electromagnetic and electrica
19、l properties 5 5.1 Coercivity H cand retentivity B r 5 5.2 Coating resistance 5 6 Tape properties measured on a video tape recorder 5 6.1 Video properties 5 6.2 Audio properties 6 Annex ZA (normative) Other international publications quoted in this standard with the references of the relevant europe
20、an publications 13 Figure 1a Test system for dynamic measurementof longitudinal curvature 8 Figure 1b Test system for dynamic measurementof longitudinal curvature 9 Figure 2 Test system for the measurement of thecoefficient of friction 10 Figure 3 Test system for dynamic measurementof friction 11 Fi
21、gure 4 Test system for the measurement ofcoating resistance 12 Figure 5 Procedure adopted in the case of difficulties in finding exact peak 12 latest date of publication of an identical national standard (dop)1992-10-15 latest date of withdrawl of conflicting national standards (dow)1992-10-15EN6073
22、5:1991 BSI 10-1999 3 1 Scope This standard describes the measuring methods for evaluation of the properties of magnetic tapes used for video recorders. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International
23、 Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties 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
24、 of IEC and ISO maintain registers of currently valid International Standards. IEC 698:1981, Measuring methods for television tape machines. IEC 883:1987, Measuring method for chrominance signal-to-random noise ratio for video tape recorders. IEC 1105:1991, Reference tapes for video tape recorder sy
25、stems (being printed). ISO 468:1982, Surface roughness Parameters, their values and general rules for specifying requirements. ISO/R 527:1966, Plastics Determination of tensile properties. CCIR Recommendation 567-2 Recommendations and reports of the CCIR(1986) Volume XII Transmission of sound broadc
26、asting and television signals over long distances (CMTT). 3 Testing environment All properties, if not otherwise specified, shall be measured at a temperature of20 C 1 C at a humidity of48% to52% and an atmospheric pressure between86kPa and106kPa. The test sample to be measured shall be stored for24
27、h in the above conditions to ensure correct testing results. This is defined as the standard 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 c
28、alibrated microscope or profile projector having an accuracy better than24m. The tape width shall be defined as the average of the five readings. 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 sect
29、ions on top of each other in a suitable manner, measuring with a micrometer gauge and dividing the reading by ten. 4.3 Tensile tests The measurements are made in accordance with ISO/R527. The length of the test sample shall be200mm. The rate of elongation for all tensile tests shall be100mm/min (ISO
30、/R527, rate D). 4.3.1 Breaking strength The sample shall 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 (F5%) The yield strength (F5% shall be defined as the force necessary to pro
31、duce5% elongation of the tape. 4.4 Residual elongation To measure the residual elongation, a test sample of approximately1m shall be subjected to a tension of50N/mm 2total cross-section for a period of3min. The sample shall then be measured with negligible force(0,25N)3min after the load has been re
32、moved. The residual elongation shall be stated as a percentage of the original tape length. 4.5 Longitudinal shrinkage A test sample (approximately1m) shall be stored in the standard environment for48h. It shall then be vertically suspended and loaded with0,25N. Thelength of the test sample,3min aft
33、er the load has been applied, shall be defined as the original tape length. The environment shall be then changed to50 C and13% relative humidity for a period of18h. Three hours after restoring the standard environment, the shrinkage of the sample shall be measured and expressed as a percentage of t
34、he original tape length. 4.6 Coefficient of elongation in humidity A test sample (approximately1m) shall be stored in the standard environment for48h. It shall then be vertically suspended and loaded with0,25N. Thelength of the test sample,3min after the load has been applied, shall be defined as th
35、e original tape length.EN60735:1991 4 BSI 10-1999 After increasing the relative humidity by30% for a period of18h the elongation shall be measured and expressed as a percentage of the original tape length. 4.7 Transverse cupping A tape sample of10mm length shall be placed, concave side down, on a sm
36、ooth 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 least1h. The tape sample and the test surface shall not be charged electrostatically. 4.8 Longitudinal curvature 4.8.1 Stat
37、ic longitudinal curvature A tape sample of1m 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 curvature. 4.8.2 Dynam
38、ic measuring of longitudinal curvature The test sample shall be measured in a test arrangement according to Figure 1a andFigure 1b. The variation of the tape edge shall be measured with a light sensor through a slot of1mm width, in the area of the lower tape edge. The outpout signal shall be proport
39、ional 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 diameter of100mm
40、 and a surface roughness Ra=0,254m in accordance with ISO468. 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. Procedure: with a velo
41、city of5cm/min the test sample with its coating side facing the test drum shall be pulled over the drum for2min. After a short pause the procedure can be started under the same conditions and the results recorded. Coefficient of friction 4.9.2 Quasi-static friction of the reverse side The drum shall
42、 be replaced by a stainless steel pin of8mm diameter and a surface roughnessRa=0,074m. For particular applications, a pin of different material and different surface roughness may be used. The test procedure is as detailed in4.9.1 except that the reverse side of the tape is facing the pin surface. 4
43、.9.3 Dynamic friction of the coating side The dynamic friction shall be measured with the equipment shown in Figure 3. This machine is capable of varying the speed in the range from0.5cm/s to about20cm/s. For material of drum and pin, see4.9.1 and4.9.2. When a tape is run from0,5cm/s to about20cm/s,
44、 the maximum value of4 and the 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 F 2is at a maximum and at a specified speed, characteristic for the reco
45、rding equipment. The frictional 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 in4.9.3, except tha
46、t the reverse side is facing the pin. 4.10 Layer-to-layer adhesion A tape of1m in length shall be wound on a glass tube of36mm diameter at a tension of5N/mm 2with one end of the tape fixed to the glass tube. The wound test piece shall be kept at a temperature of45 C 3 C and relative humidity of80% f
47、or4h, and afterwards under the standard environment for24h. For some special applications requiring more stringent test conditions, the tape sample is wound on a12,7mm diameter tube of non-oxidizing material and exposed to a temperature of54 C and relative humidity of84% for16h and afterwards to the
48、 standard environment for24h. Finally, the test piece shall be unwound slowly with a0,1N load at the end. Then any tendency of tape sticking and delamination of magnetic coating shall be observed. where: ! is the angle of wrap around the drum (;) in radians F 1 = 0,5N load F 2 = F 1+friction. (Value
49、s of velocity and load are chosen for practical reasons). 4 1 ! - ln F 2 F 1 - =EN60735:1991 BSI 10-1999 5 4.11 Video head wear Tape tension, head mounting, pole 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 for100 passes of at least45 min each pass and the decrease of head protrusio
