Some standard content:
Professional Standard of the People's Republic of China
ZB G83 001—89
Adjusted to: HG358-1p8
35mm movie recording magnetic disc
Published on December 14, 1989
Published by the Ministry of Chemical Industry of the People's Republic of China and implemented on March 1, 1990
Professional Standard of the People's Republic of China
35mm movie recording magnetic disc
1 Subject content and scope of application
1.1 Subject content
ZB G83 001---89
Adjusted to 2 HG/T 3568 -- 1989
This standard specifies the terminology, classification and specifications, technical requirements, test methods, inspection rules and packaging, and storage conditions for 35mm electric recording magnetic discs.
1.2 Scope of application
This standard applies to magnetic recording discs used for recording language, music, effects, mixing, etc. during the film production process. 2 Terminology
2.1 Reference voltage
When replaying the reference magnetic calibration tape, the output voltage of the recording recorder playback channel is set to "0 dB". 2.2 Calibration disc
A signal disc that records a signal with specified characteristics and is used to calibrate the recording recorder playback channel. 2.3 Base disc
A blank disc with specified characteristics that is used as a reference for disc testing and a reference for measuring recorders. This standard stipulates that the West German DIN15538 standard disc is used as the first reference disc, and the second reference disc (transverse disc) is manufactured by the First Film Factory of the Ministry of Chemical Industry and is recommended for use, and the correction values of the second reference disc and the DIN15538 standard disc are given. The reference magnetic sheet is issued by the Ministry of Chemical Industry's magnetic recording material standardization technical coordination unit. 2.4 Reference bias
The reference bias is the optimal bias required for the reference magnetic sheet. This standard stipulates that the bias current corresponding to the 1dB drop after the peak of the 1kHs signal output level of the reference magnetic sheet is the reference bias. 3 Product classification and specifications
3.1 Product classification
According to the different film base materials used, it is divided into T type and P type. T type movie recording magnetic sheet: The film base is made of triacetyl cellulose, and the back of the magnetic sheet is printed with the word "T\", and the magnetic serial number and date are printed.
P type movie recording magnetic sheet: The film base is made of polyester, and the back of the magnetic sheet is printed with the word "p\", and the magnetic serial number and date are printed. 3.2 Product specifications shall comply with the provisions of Table 1. Table 1
Magnetic sheet length, n
Core size, mm
Note: 1), 2) Dimensional drawing Appendix A.
35×1001>
Approved by the Ministry of Chemical Industry of the People's Republic of China on December 14, 1989 T
305, 320
35×803
Implementation on March 1, 1990
Technical indicators
4.1 Electroacoustic performance indicators shall comply with the provisions of Table 2. Item
Bias ratio, dB
Relative sensitivity, dB
Third harmonic distortion, %
Maximum output level, B
Reference level to bias noise ratio,
Reference level to DC sound ratio,
Smearing degree dB
Uniformity, dB
10 kHz
10 kHz
ZB G83 001—89
—Product
4.2 Geometric dimensions and physical and mechanical performance indicators shall comply with the requirements of Table 3 Table 3
Magnetic sheet width, mm
Magnetic sheet thickness, um
Tooth hole size
Service force, N
Longitudinal continuous bending, mm
Transverse bending
Abrasion resistance, times
5 Electroacoustic performance test method
5.1 Technical requirements for the use of test equipment and instruments 5.1.1 Test recorder
34.97±0.03
Qualified product
34.97±0. 03
ZB G83 001--89
Drive speed: 45.6cm/s, error ±0.2%; Recording head gap length: 18ums
Playback head original gap length: 10um;
Track width, 5μm
Bias and erase requirements: The voltage frequency supplied to the bias and erase heads is greater than or equal to 80kHz, and the bias even harmonic distortion is less than or equal to 0.05%;
Dither rate: ≤0.08%
Signal to noise ratio: ≥66dB.
Signal generator
Frequency range: 20~20kHz;
Amplitude error, ±0.5dB;
Frequency error: 1Hz,
Total harmonic distortion: ≤0.1%,
Output impedance; ≤5k2.
Electronic millivoltmeter
Range: 1mV~100V
Frequency response: 20 Hz~~20 kHz, error ±0. 5 dB; Input impedance: 6002. www.bzxz.net
Bandpass filter
Center frequency: 1 kHz, 3 kHz;
Selectivity: Attenuation from center frequency to 1/3 octave is greater than or equal to 20dB; Signal-to-noise ratio: 270dB.
Level recorder
Recording pen speed: 500mm/s for 100 recording paper width); Recording paper speed, 3mm or 1mm/s.
High frequency ammeter
Range, 0~~50mA;
Frequency range: 20~500kHz
5.2 Test conditions
Environmental temperature: 15~25℃,
Relative humidity: 45%~75%
Calibration magnetic disc DIN15538;
Reference magnetic disc: in accordance with the provisions of Article 2.5
5.3 When testing the electroacoustic performance of the magnetic disc, a full-disk magnetic disc should be used. Unless otherwise specified, the electrical performance test system is carried out as shown in the figure below. Test at the desired point,
Signal generator
5.5 Test method
5.5.1 Bias ratio
Amplifier
Rated current meter
Magnetic resonator
ZB G83 001—89
Technical amplifier
Electrical performance test system diagram
Band filter
A weighting network
Electronic millivoltmeter
Level recorder
On the reference magnetic sheet, input a 10B level and record a 1kHz signal. Gradually increase the bias current until the signal output level reaches the peak. Increase the bias current again until the output level drops by 1dB, and record this bias current as 1. On the magnetic sheet to be tested, use the same method to measure the bias current as 11. The bias ratio is calculated as follows: Bias ratio (dB) = 201g
5.5.2, Relative sensitivity
On the magnetic disk under test and the reference magnetic disk, use the reference bias and input a 10dB level, and record the 1kHz and 10kHz signals respectively. Play the sound and measure the difference in output voltage between the magnetic disk under test and the reference magnetic disk at the same frequency, in dB. 5.5.3 Third harmonic distortion
On the magnetic disk under test, use the reference bias and record the 1kHz signal. Adjust the input so that the output level reaches 0dB, and measure the ratio of the third harmonic of the signal to the fundamental amplitude, expressed in percentage. 5.5.4 Maximum output level
On the magnetic disk under test, use the reference bias and record the 1kHz signal, adjust the input, and measure the difference between the output level and the reference level when the third spectrum distortion reaches 3%, expressed in decibels. On the magnetic disk under test, use the reference bias and record the 10Hz signal. Adjust the input to make the output level reach the maximum, and then continue to increase the input without the output level changing significantly. Note the level at this time, and calculate the difference between the level and the reference level, expressed in decibels. 5.5.5 Bias-to-noise ratio
On the magnetic disk under test, use the reference bias and 6000 input impedance to record without signal. Then rewind the magnetic disk under test and play the sound. Measure the difference between the playback level and the reference level, expressed in decibels. 5.5.6 Reference level to DC noise ratio
ZB G83 001 89
On the magnetic disk under test, use the reference bias to record a 1kHz signal, and measure the recorded current value (effective value) when the output reaches the 0dB level. Then, switch to a DC record with the same value (turn the switch from 2 to 1 in the center of Figure 1), and measure the difference between the noise level and the reference level, expressed in decibels.
5.5.7 Degree of erasure
On the magnetic disk under test, use a 1kHz signal to record a level 6dB higher than the reference level. Rewind the disk and erase the recorded signal. Measure the residual signal level (through a 1kHz bandpass filter). Calculate the difference between the residual signal and the disk level before erasure, expressed in decibels. 5.5.8 Uniformity
On the magnetic disk under test, use a reference bias magnet, input a 10dB level, and record 1kHz and 10kHz signals. Play back the magnetic disk under test, and use a level recorder at the output to record the level change curves of the two frequencies respectively. Take the deviation of the peak point (maximum value) and valley point (minimum value) of the curve from the baseline, expressed in decibels.
6 Measurement methods for geometric dimensions and physical and mechanical properties 6.1 Measurement equipment and instruments
6.1.1 Tensile testing machine
Range 0300N:
Accuracy: IN.
6. 1. 2 Micrometer
Range: 0200μm
Accuracy: lum.
6.1.3 Reading microscope
Range: 0~200mmz
Accuracy: 0.005.
6.2 Measuring environment
Temperature: 15~～25C
Relative humidity: 45%～75%.
6.3 Measuring method
6.3.1 Width of magnetic sheet
Select any five points in the longitudinal direction of the magnetic sheet to be measured, and the distance between adjacent points shall not be less than 1m. When measuring the width with a reading microscope, it shall comply with the regulations. 6.3.2 Thickness of magnetic sheet
Select any five points in the longitudinal direction of the magnetic sheet to be measured, and the distance between adjacent points shall not be less than 1m. When measuring the width with a micrometer, it shall comply with the regulations. 6.3.3 Tooth hole size
For the size of the tooth hole, see Appendix B. Measure according to the provisions in HG7--1350 and it should meet the requirements. 6.3.4 Yield force
Take a magnetic sheet to be tested with a length of 200mm and a width of 35tmm (with tooth holes on both sides), place it in the clamp of the tensile testing machine and fix it (the clamp spacing is 100mm), stretch it at a constant speed of 100mm/min, and when the magnetic sheet produces 3% elongation, measure the force applied, expressed in Newton. 6.3.5 Longitudinal bending
Take a magnetic sheet to be tested with a length of 1m, make its two sides close to the standard ruler and fix it. Measure the maximum deviation between any point between the two ends of the edge of the base magnetic sheet and the standard ruler, which should meet the requirements. 6.3.6 Horizontal bending
Take any section of the magnetic sheet to be tested, place it on the standard push platform with the magnetic layer facing upward, and make the gauge contact the magnetic sheet at 90°. Measure the bending degree, which should meet the requirements.
6.3.7. Wear resistance
Take a 1.5m long magnetic sheet, use the reference bias magnet, input a 10dB level, and record at 4kHz. Then play ZB G83 001-89
on the recorder in a loop, and use the level recorder to record the curve changes. The first time is the initial curve. Within the specified number of cycles, compare the last time with the initial curve, and the drop amplitude shall not exceed 1 dB.
Note: the magnetic sheet is not allowed to carry the recorder head during the release process. ? Inspection rules
7.1 This rule applies to the quality inspection department of the manufacturer and the user unit. 7.2 The acceptance inspection method of this rule shall be in accordance with GB 2828. According to the different requirements for product inspection performance, it is divided into Group A, Group B and Group C. 7.3 According to the relevant provisions of GB2828, the inspection level in Table 4 is determined as the quality level of acceptance inspection. It is also possible to set acceptance rules for product quality acceptance based on the negotiation between the supply and demand parties. Table 4 Acceptance inspection quality level
Packaging and marking
Special inspection level
Qualified quality disk level (AQL)
8.1 After demagnetization, the finished magnetic disk is packed in small boxes per disk. Inspection content
Appearance, magnetic disk scratches, tooth holes, disk edge burrs and disk defects Electrical properties; relative sensitivity, uniformity, maximum output level Physical properties, strictness, lateral bending, abrasiveness 8.1.1 The box contains a product certificate, and the product production batch number and the inspection personnel seal are indicated. 8.1.2 The box is affixed with a trademark, and the manufacturer, product model, specifications and ex-factory date are printed. 8.2 Products with the same shaft number or equivalent performance indicators should be packed in bulk. 8.2.1 The name and box number of the product should be indicated on the packaging box, and it should be marked with moisture-proof, sun-proof, and shock-proof. 9 Storage of parts
9.1 When magnetic disks are stored for a long time, they should be concentrated in the magnetic disk warehouse. The warehouse should have good air-conditioning facilities to maintain the following environmental conditions. Ambient temperature: 15~25℃:
Relative humidity: 45%~75%.
9.2 Magnetic disks should be kept away from strong magnetic fields.
DD
ZB G83 00189
Appendix A
Pancong Ruler
(Supplement)
(08)001
ARC Section
Film Magnetic Disc Shaft Core
Material Numbers Plastic
Note: This part will not be processed after injection molding. Therefore, the surface after molding should be smooth, especially the outer and inner surfaces, and there should be no mold seam and flash. The two types of cores in this figure have the same dimensions except for the different sizes in brackets. Name
Sheet width A, mm
Sprocket hole vertical span A, mm
Sprocket hole width C, mm
Sprocket hole height 9, mm
Sprocket hole distance, mm
Sprocket hole horizontal span F, mm
Sprocket hole stagger G, mm
Sprocket hole angular radius R, mm1
Continuous 100 hole spacing L. mm
Additional instructions:
ZB G8 3 001 89
Magnetic sheet hole shape size
(Supplement)
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and drafted and managed by the First Film Factory of the Ministry of Chemical Industry. The main drafter of this standard is Li Fenglin.
34. 97± 0. 03
4.7500. 015
2. 8000. 015
1. 980= 0. 015
2. 00 0. 05
28. 17-+0. 05
475.0±0. 4
People's Republic of China
Professional Standard
35mm Film Recording Disk
ZB G83 00189
Published by China Standards Press
(Beijing Fuwai Sanguohe)
China Standards Press, Beijing Printing Factory, Xinhua Bookstore, Beijing Distribution Office, Xinhua Bookstores in all regions, copyright reserved, no reproduction allowed
Format 880×12301/16 Printing sheet 3/4
Word count 16000
First printing in October 1990
First edition in October 1990
Print run 1-1500
Book number: 155066-2-7653
Price 0.75 yuan
. Standard month 147-—33
68821/5m
t00-289,84 Yield force
Take a 200mm long and 35tmm wide (with tooth holes on both sides) magnetic sheet to be tested, place it in the fixture of the tensile testing machine and fix it (the distance between the fixtures is 100mm), stretch it at a constant speed of 100mm/min, and when the magnetic sheet produces 3% elongation, measure the force applied, expressed in Newton. 6.3.5 Longitudinal bending
Take a 1m long magnetic sheet to be tested, make its two sides close to the standard ruler and fix it. Measure the maximum deviation between any point between the two ends of the edge of the base magnetic sheet and the standard ruler, which should meet the requirements. 6.3.6 Transverse bending
Take any section of the magnetic sheet to be tested, place it on the standard push platform with the magnetic layer facing up, make the gauge contact the magnetic sheet at 90°, and measure the curvature, which should meet the requirements.
6.3.7. Wear resistance
Take a 1.5m long magnetic sheet, use the reference bias magnet, input a 10dB level, and record at 4kHz. Then play ZB G83 001-89
on the recorder in a loop, and use a level recorder to record the curve changes. The first time is the initial curve. Within the specified number of cycles, compare the last time with the initial curve, and the drop amplitude is not greater than 1 dB.
Note: The magnetic sheet is not allowed to carry the recorder head during the release process. ? Inspection rules
7.1 This rule applies to the quality inspection department of the manufacturer and the user unit. 7.2 The acceptance inspection method of this rule is in accordance with GB 2828. According to the different requirements for product inspection performance, it is divided into Group A, Group B, and Group C. 7.3 According to the relevant provisions of GB2828, the inspection level in Table 4 is determined as the acceptance inspection quality level. The acceptance rules for product quality can also be set according to the negotiation between the supply and demand parties. Table 4 Acceptance inspection quality level
Packaging and marking
Special inspection level
Qualified quality disk level (AQL)
8.1 After demagnetization, the finished magnetic disks are packed in small boxes per disk. Inspection content
Appearance, magnetic disk scratches, tooth holes, burrs on the edge of the disk and disk defects Electrical properties; relative sensitivity, uniformity, maximum output level Physical properties, strictness, lateral bending, abrasion resistance 8.1.1 The box contains the product certificate, and the product production batch number and the inspection personnel seal are indicated. 8.1.2 The box surface is affixed with a trademark, and the manufacturer, product model, specifications and ex-factory date are printed. 8.2 Products with the same axis number or equivalent performance indicators are packed in large packages. 8.2.1 The name and box number of the product should be indicated on the packaging box, and the words moisture-proof, sun-proof and shock-proof should be marked. 9 Storage Parts
9.1 When magnetic disks are stored for a long time, they should be concentrated in a disk warehouse. The warehouse should have good air conditioning facilities to maintain the following environmental conditions. Ambient temperature: 15~25℃:
Relative humidity: 45%~75%.
9.2 Magnetic disks should be kept away from strong magnetic fields.
DD Part
ZB G83 00189
Appendix A
Pancong Ruler
(Supplement)
(08)001
ARC Section
Film Magnetic Disk Shaft Core
Material Number Plastic
Note: This part will not be processed after injection molding. Therefore, the surface after molding should be smooth, especially the outer and inner surfaces, and there should be no mold seam core and flash. The two types of cores in this figure have the same dimensions except for the different sizes in brackets. Name
Sheet width A, mm
Sprocket hole vertical span A, mm
Sprocket hole width C, mm
Sprocket hole height 9, mm
Sprocket hole distance, mm
Sprocket hole horizontal span F, mm
Sprocket hole stagger G, mm
Sprocket hole angular radius R, mm1
Continuous 100 hole spacing L. mm
Additional instructions:
ZB G8 3 001 89
Magnetic sheet hole shape size
(Supplement)
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and drafted and managed by the First Film Factory of the Ministry of Chemical Industry. The main drafter of this standard is Li Fenglin.
34. 97± 0. 03
4.7500. 015
2. 8000. 015
1. 980= 0. 015
2. 00 0. 05
28. 17-+0. 05
475.0±0. 4
People's Republic of China
Professional Standard
35mm Film Recording Disk
ZB G83 00189
Published by China Standards Press
(Beijing Fuwai Sanguohe)
China Standards Press, Beijing Printing Factory, Xinhua Bookstore, Beijing Distribution Office, Xinhua Bookstores in all regions, copyright reserved, no reproduction allowed
Format 880×12301/16 Printing sheet 3/4
Word count 16000
First printing in October 1990
First edition in October 1990
Print run 1-1500
Book number: 155066-2-7653
Price 0.75 yuan
. Standard month 147-—33
68821/5m
t00-289,84 Yield force
Take a 200mm long and 35tmm wide (with tooth holes on both sides) magnetic sheet to be tested, place it in the fixture of the tensile testing machine and fix it (the distance between the fixtures is 100mm), stretch it at a constant speed of 100mm/min, and when the magnetic sheet produces 3% elongation, measure the force applied, expressed in Newton. 6.3.5 Longitudinal bending
Take a 1m long magnetic sheet to be tested, make its two sides close to the standard ruler and fix it. Measure the maximum deviation between any point between the two ends of the edge of the base magnetic sheet and the standard ruler, which should meet the requirements. 6.3.6 Transverse bending
Take any section of the magnetic sheet to be tested, place it on the standard push platform with the magnetic layer facing up, make the gauge contact the magnetic sheet at 90°, and measure the curvature, which should meet the requirements.
6.3.7. Wear resistance
Take a 1.5m long magnetic sheet, use the reference bias magnet, input a 10dB level, and record at 4kHz. Then play ZB G83 001-89
on the recorder in a loop, and use a level recorder to record the curve changes. The first time is the initial curve. Within the specified number of cycles, compare the last time with the initial curve, and the drop amplitude is not greater than 1 dB.
Note: The magnetic sheet is not allowed to carry the recorder head during the release process. ? Inspection rules
7.1 This rule applies to the quality inspection department of the manufacturer and the user unit. 7.2 The acceptance inspection method of this rule is in accordance with GB 2828. According to the different requirements for product inspection performance, it is divided into Group A, Group B, and Group C. 7.3 According to the relevant provisions of GB2828, the inspection level in Table 4 is determined as the acceptance inspection quality level. The acceptance rules for product quality can also be set according to the negotiation between the supply and demand parties. Table 4 Acceptance inspection quality level
Packaging and marking
Special inspection level
Qualified quality disk level (AQL)
8.1 After demagnetization, the finished magnetic disks are packed in small boxes per disk. Inspection content
Appearance, magnetic disk scratches, tooth holes, burrs on the edge of the disk and disk defects Electrical properties; relative sensitivity, uniformity, maximum output level Physical properties, strictness, lateral bending, abrasion resistance 8.1.1 The box contains the product certificate, and the product production batch number and the inspection personnel seal are indicated. 8.1.2 The box surface is affixed with a trademark, and the manufacturer, product model, specifications and ex-factory date are printed. 8.2 Products with the same axis number or equivalent performance indicators are packed in large packages. 8.2.1 The name and box number of the product should be indicated on the packaging box, and the words moisture-proof, sun-proof and shock-proof should be marked. 9 Storage Parts
9.1 When magnetic disks are stored for a long time, they should be concentrated in a disk warehouse. The warehouse should have good air conditioning facilities to maintain the following environmental conditions. Ambient temperature: 15~25℃:
Relative humidity: 45%~75%.
9.2 Magnetic disks should be kept away from strong magnetic fields.
DD Part
ZB G83 00189
Appendix A
Pancong Ruler
(Supplement)
(08)001
ARC Section
Film Magnetic Disk Shaft Core
Material Number Plastic
Note: This part will not be processed after injection molding. Therefore, the surface after molding should be smooth, especially the outer and inner surfaces, and there should be no mold seam core and flash. The two types of cores in this figure have the same dimensions except for the different sizes in brackets. Name
Sheet width A, mm
Sprocket hole vertical span A, mm
Sprocket hole width C, mm
Sprocket hole height 9, mm
Sprocket hole distance, mm
Sprocket hole horizontal span F, mm
Sprocket hole stagger G, mm
Sprocket hole angular radius R, mm1
Continuous 100 hole spacing L. mm
Additional instructions:
ZB G8 3 001 89
Magnetic sheet hole shape size
(Supplement)
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and drafted and managed by the First Film Factory of the Ministry of Chemical Industry. The main drafter of this standard is Li Fenglin.
34. 97± 0. 03
4.7500. 015
2. 8000. 015
1. 980= 0. 015
2. 00 0. 05
28. 17-+0. 05
475.0±0. 4
People's Republic of China
Professional Standard
35mm Film Recording Disk
ZB G83 00189
Published by China Standards Press
(Beijing Fuwai Sanguohe)
China Standards Press, Beijing Printing Factory, Xinhua Bookstore, Beijing Distribution Office, Xinhua Bookstores in all regions, copyright reserved, no reproduction allowed
Format 880×12301/16 Printing sheet 3/4
Word count 16000
First printing in October 1990
First edition in October 1990
Print run 1-1500
Book number: 155066-2-7653
Price 0.75 yuan
. Standard month 147-—33
68821/5m
t00-289,8mm
Tooth hole staggered amount G, mm
Tooth hole angular radius R, mm1
100 consecutive hole spacing L. mm
Additional instructions:
ZB G8 3 001 89
Magnetic sheet hole shape dimensions
(Supplement)
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and was drafted and managed by the First Film Factory of the Ministry of Chemical Industry. The main drafter of this standard is Li Fenglin.
34. 97± 0. 03
4.7500. 015
2. 8000. 015
1. 980= 0. 015
2. 00 0. 05
28. 17-+0. 05
475.0±0. 4
People's Republic of China
Professional Standard
35mm Film Recording Disk
ZB G83 00189
Published by China Standards Press
(Beijing Fuwai Sanguohe)
China Standards Press, Beijing Printing Factory, Xinhua Bookstore, Beijing Distribution Office, Xinhua Bookstores in all regions, copyright reserved, no reproduction allowed
Format 880×12301/16 Printing sheet 3/4
Word count 16000
First printing in October 1990
First edition in October 1990
Print run 1-1500
Book number: 155066-2-7653
Price 0.75 yuan
. Standard month 147-—33
68821/5m
t00-289,8mm
Tooth hole staggered amount G, mm
Tooth hole angular radius R, mm1
100 consecutive hole spacing L. mm
Additional instructions:
ZB G8 3 001 89
Magnetic sheet hole shape dimensions
(Supplement)
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and was drafted and managed by the First Film Factory of the Ministry of Chemical Industry. The main drafter of this standard is Li Fenglin.
34. 97± 0. 03
4.7500. 015
2. 8000. 015
1. 980= 0. 015
2. 00 0. 05
28. 17-+0. 05
475.0±0. 4
People's Republic of China
Professional Standard
35mm Film Recording Disk
ZB G83 00189
Published by China Standards Press
(Beijing Fuwai Sanguohe)
China Standards Press, Beijing Printing Factory, Xinhua Bookstore, Beijing Distribution Office, Xinhua Bookstores in all regions, copyright reserved, no reproduction allowed
Format 880×12301/16 Printing sheet 3/4
Word count 16000
First printing in October 1990
First edition in October 1990
Print run 1-1500
Book number: 155066-2-7653
Price 0.75 yuan
. Standard month 147-—33
68821/5m
t00-289,8
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