Recorded characteristics for magnetic sound records on 35mm and 16mm motion-picture films containing no picture

This standard specifies the recording characteristics and the tolerance range of the recording level of 35mm magnetic film with a film speed of 24 frames/s (45.6cm/s) or 25 frames/s (47.5cm/s) and 16mm magnetic film with a film speed of 24 frames/s (18.3cm/s) or 25 frames/s (19.05cm/s). GB/T 5875-1994 Recording characteristics of 35mm and 16mm magnetic film GB/T5875-1994 Standard download decompression password: www.bzxz.net
This standard specifies the recording characteristics and the tolerance range of the recording level of 35mm magnetic film with a film speed of 24 frames/s (45.6cm/s) or 25 frames/s (47.5cm/s) and 16mm magnetic film with a film speed of 24 frames/s (18.3cm/s) or 25 frames/s (19.05cm/s).

National Standard of the People's Republic of China
Recorded charucteristies for magnetics
Recorded charucteristies for magnetics
35mmand16mmmotian-pleture films containing no plctureGB/T 5875-.94
Replaces GB 7426--87
GB 5875-86
This standard is equivalent to the international standard IS01189-1986 "Technical requirements for recording characteristics of 35mm magnetic films" and ISO11881984 "Technical requirements for recording characteristics of 16mm magnetic films". 1 Subject matter and scope of applicationbzxz.net
This standard specifies the recording characteristics and permissible range of recording levels of 35mm magnetic film with a film speed of 24 frames/s (45.6cm/s) or 25 frames/s (47.5cm/s) and 16mm magnetic film with a film speed of 24 frames/s (18.3cm/s) or 25 frames/s (1905cm/s). 2 Terminology
Magnetic film
A magnetic sound carrier made according to the geometric dimensions and perforation specifications of motion picture film. 3 Recording characteristics
3.1 When a sinusoidal signal of equal amplitude is applied to the input end of the recording system, the rated rate of the short-circuit flux Φ recorded on the magnetic disk should be consistent with the impedance characteristics of the RC parallel network with a time constant of ". Its characteristics are expressed by the following formula: Le = Ca - 10lag:o(1 + 4r'f+*) In the formula, L.--relative value of short-circuit flux, dB; frequency, H2;
-time constant. For 35 mm magnetic disk recording, =35 μs, for 16 mm recording, =70 μsC, a constant, for 35 mm magnetic disk recording, when the reference frequency is 1 000 Hz, let L.=0. From this, the approximate value of Cs is calculated to be 0.205dH, for 16 mm magnetic disk recording, when the reference frequency is 400Hz, let L,=0, from this, the approximate value of C, is calculated to be 0.132 dB, the approximate values ​​of recording characteristics are shown in Table 1 and Table 2.
Table 135 mm magnetic disk recording characteristics (approximate values) Frequency, Hz
Relative value of short-circuit magnetic flux, dB
Approved by the State Administration of Technical Supervision on December 28, 1994 Frequency, Hz
Relative value of short-circuit magnetic flux, d
Implementation on August 1, 1995
Particle frequency, Hz
Frequency, Hz
3.2 Corresponding sound reproduction characteristics
GB/T 5875
ContinuedTable 1
Relative value of short-circuit flux,
Rate, Hs
Table 216mm magnetic disc recording characteristics (approximate values)Relative value of short-circuit flux, dB
Relative value of short-circuit flux, Hz
Relative value of short-circuit flux, dB
Relative value of short-circuit flux, tH
The soundtrack recorded in accordance with 3.1 should obtain a flat frequency response when reproduced in a standard reproduction system. Permissible error
On 35mm or 16mm magnetic discs, the characteristics specified in 3.1 should be obtained. When recording, the tolerance should not exceed the range given in Figure 1 or Figure 2 when the standard sound reproduction system is used for sound reproduction.
Additional Notes:
GB/T5875-94
Figure 135mm magnetic recording level tolerance range
Figure 216mm magnetic recording level tolerance range
This standard is proposed by the Ministry of Radio, Film and Television of the People's Republic of China. This standard is under the jurisdiction of the China Film Science and Technology Research Institute of the Ministry of Radio, Film and Television. This standard is drafted by the China Film Science and Technology Research Institute of the Ministry of Radio, Film and Television. 5k 8.3k
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