EN IEC 60098:2020 pdf download.Analogue audio disk records and reproducing equipment(IEC 60098:2020)
4.1 Scales for graphical presentation of data
Linear or logarithmic scales are recommended for graphical presentation. Linear decibel scales are equivalent to logarithmic scales. Other kinds of scale, such as double logarithmic,should be avoided. When using decibel scales, the zero reference should, if possible, be the rated value. In those cases, where each of the scales refers directly to physical units, it is recommended to avoid a combination of linear and logarithmic scales.Where quantities represented by the axes are of the same kind, it is recommended that the same unit length be used for both.
Linear scales with remote zero point should be avoided as far as possible. For further information, see IEC 60263.
4.2 Scales for frequency characteristics
Graphs should be drawn with frequency in Hz on the x-axis with a logarithmic scale, and the level expressed in dB on the y-axis with a linear scale. The scale ratio should be such that the length representing one decade of frequency is the same as the length representing a 25 dB or a 50 dB difference in level. The preferred length per decade is 50 mm. If the size of the graph is changed, the scale ratio should be left unaltered.
6.1 Direction of groove modulation
The stereophonic groove shall carry two channels of information. The two channels shall be recorded in such a manner that they can be reproduced by movements of a reproducing stylus tip in two directions at 90° to each other, and at 45° to a radial line through the stylus tip and the centre of the record; these movements shall be tangential to, or lie in a plane through the stylus tip and the record centre, inclined at an angle of 20 +5/0。anticlockwise to the normal to the record surface through the stylus tip as viewed towards the record centre (vertical tracking angle). The resulting modulation shall be optimum for reproducing styli having a rake angle of between 0° and -5° (for detail, see Figure 3).
6.2.2 Channel phasing
The phasing of the two recorded signals shall be suitable for reproduction on two-channel equipment so connected that movement of the reproducing stylus tip along the radial line through stylus tip and disk centre (as with a monophonic record) produces in-phase sound pressures at the left-hand and right-hand loudspeakers.
6.2.3 Channel levels
The levels of the two recorded signals shall be suitable for reproduction on two-channel equipment, of identical channel gain, so connected that movement of the reproducing stylus along the radial line through the stylus tip and disk centre (as with a monophonic record) produces equal sound pressures at the left-hand and right-hand loudspeakers.EN IEC 60098 pdf download.