JB/T 8389-2001 Method for determination of projection screen characteristic parameters
Some standard content:
EC5 37.0e0.10
Machinery Industry Standard of the People's Republic of China
JI/T 8389-- 2001
Determination method for characteristic parameter of a projection screen
Videometry for characteristic parameter of a projection screen
Published on April 9, 2001
Applied on September 1, 2001
Published by China Machinery Industry Federation
JB/T 83892001
This standard is one of the series of standards of my country's silver screen. This series of standards covers reflective and transparent projection screens for movies, red lights, projection, video and special applications. The current standards include GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R, GBT13982-199R 5380--IE99
JB/T 7S09-2000
FB.T 83B9--2001
Projection effect list
Projection effect parameters
This projection effect parameter determination method is based on the standard JR183891996 and JB.8245-1915. Appendix A of this standard is the standard's counterpart. This standard is proposed and coordinated by the System Effect Research Institute of the Institute of System Regulation. The responsible unit for the drafting of this standard: Duhuangdao Taxation Bureau Machinery Research Institute: The main drafter of this standard: Qian Jishi.
1 Model
Mechanical Industry Standard of the People's Republic of China
Measurement method for characteristic parameters of projection screen
Measurement method for characteristicpurameter of projection screen This standard specifies the measurement method for reflection and incident projection screen parameters. JB/T8389—2001
3389-1926
FB/T 8245—[995
This standard applies to reflection and transmission screens for film, slide, film and video projection, and does not apply to screens for other special purposes. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through citation in this standard. When this standard was published, the versions shown were all valid. All parties to this standard shall discuss the use of the latest version of the standard. JBT5839-1503 Determination of screen characteristics
BT7809-2000
This standard adopts the following definitions.
3.1 Effective projection screen: ser
A light-reflecting or light-shielding screen with specified optical properties for projection. 3.2 Juminance factor 3 Juminance factor The ratio of the reflection or transmission area of the product to the reflection of the ideal diffuse reflector under the same lighting conditions and given viewing angles -
3.32na3index
expressed as a natural number at a specified distance: β. Effective diffusing angle 2e The luminance required for a given viewing angle should not drop by more than 3.520 52 index
expressed as a natural number at a specified distance. 2α, effective scattering self-regulation: 3.6 Comprehensive index KcpmplexineerK
The same projection screen allows the sum of 5 and 2, that is: X=P by a+ 2x m in
3.7 Sound attenuation
For any perforated reflection, the sound pressure attenuation caused by the speaker being placed behind the lead is defined as the difference between the sound attenuation of 8kHs and 12.5kHz and the sound attenuation of 50DHz, in dB. 3.8 Viewing angle viewing rngle
The angle between the normal line of the viewing center in the horizontal plane through the center of the screen and the normal line of the viewing center. 3.9 Effective angle of reflection prajactian angls intermediate sugar industry residual alloy 2001-04-09 approved 200-09-01 implementation
the angle between the optical axis and the normal line of the reflection. AB/T 8389-2001
4 Determination of the effective scattering of silver 4.1 Micro-measurement
4.1.1 A dark room without reflective surface. The maximum area is not less than 5m×3.5m: 4.1.2 A projection device with a stable light source, such as a multi-purpose slide projector; 4.13 A frame for hanging steel samples in an orderly manner; 4.1.4 A degree index that can indicate the position of the display screen. The indication range is 0° and 80° respectively. The indication level should not be lower than 0.5°. 1.1.5. The luminance meter with a fixed support should be installed with a 10-meter luminance meter. The spectral sensitivity of the luminance meter should conform to the 1931 International Conference on Weights and Measures (Cubdicatinn 17) for the light sensitivity of the observer. 4.1.6. The total time-varying standard is not caused by the standard board environment (0 seal end technology is determined by the pressure: 4.2 measurement bar || tt || 4.2.1 very standard on the whole frame hanging into the straight position and water, the original table is strictly viewed. The size of the elastic product is 29 yuan 1 × 0trrn width × business! The minimum area of the sample test area shall not be less than 650rum4.2.2 taste the noise placement device. Make the object sharp light axis of the product surface and pass through its center. The projection device projects light The fixed angle of the beam should not exceed 0°. And the whole product should be correct. The distance between the filter and the filter should be slightly larger than the maximum distance of the meter. 4.2.3 The filter distance of the filter should not be less than 1 meter, and should not be greater than 2 meters. 4.2.4 In order to maintain the consistency of the measurement position, after the actual distance is determined, there should be a center circle mark or a center mark with a diameter slightly larger than the measurement diameter at the center of the product. The relationship between the measurement base distance and the meter connection is as follows: d = 2t -tg0.5p
single measurement diameter,;
where: ——
L—The distance between the brightness meter and the center point of the screen, mm: the brightness meter is focused, \).
4.2.5 During the measurement, the ambient light should be shielded so that the illumination of the disturbing light on the sample surface is not greater than Ek:
Figure! Reflection brightness coefficient (in the horizontal plane) 4.3 Measurement steps
4.3.1 Under the conditions of 4.2, as shown in Figure!, place the brightness standard plate with known brightness coefficient on the center of the sample and parallel to it.
4.3.2 Without starting the projection device and focusing, place the brightness meter on a horizontal plane passing through the center of the sample, with its optical axis 5\ horizontally aligned with the center of the screen sample surface, and measure the surface reflectance of the diffuse reflection standard plate. JB/T 83R9·-2001
4.3.3 Remove the diffuse reflectance standard plate and measure the reflected reflection and the reflected reflection of the center of the sample surface with a meter under the same conditions. 4.3.4 Use formula 121 to measure the reflected reflection coefficient of the sample accurately to the second smallest effective point. B=[L.?-,
Where:--Brightness coefficient:
L,——5\reflected brightness after the first reflection.nd5-the relative brightness of the sample without reflection, t/m:-diffuse reflectance standard plate with known width, 12
4.3.5 After completing the example L, the effective angle of 2 should be measured immediately. As shown in Figure 2, extend the brightness meter on the horizontal plane with equal full distance to the normal line of the required observation and gradually increase the negative angle. Please adjust the change on the meter. When the shell brightness reading gradually drops to the upper value of 12, the angle between the double line at the brightness meter and the normal line of the center of the silver set is about 12. When the two are symmetrical, then twice of 12 is the effective reflection angle. The reading is corrected to 0.5. When the brightness is increased to 80° and its effective value is still greater than 1/2 of the original value, the viewing angle is increased again for measurement. The conclusion is that the effective reflectance is greater than 16°; it is read as diffuse reflection. At the same time, the actual value L should be measured at 80° to determine its brightness percentage. When the two values are asymmetrical, the reasons should be found, such as the short is not straight, the light is not straight and the surface is not symmetrical. If the two values are still asymmetrical when the test is performed normally, the smaller value should be taken as the effective reflectance. LS
Figure 4.4 Reflection coefficient characteristic curve
4.4. When necessary, the brightness coefficient characteristic curve can be drawn in the horizontal plane. The brightness coefficient value of 4.3 is measured once every 5 points and then divided into 2 points on the side. The method in the appendix is used to draw the true brightness coefficient characteristic curve. By comparison, only the measurement method can be used to measure every 5 points on one side, and the full-line graph can be drawn symmetrically. The brightness coefficient characteristic curve can be drawn in rectangular coordinates: there are two types of surface speed: rectangular coordinates and rectangular coordinates. Due to its acquisition characteristics, rectangular coordinates are required to draw the curve, and the expression is also completely super. Without any explanation, the brightness coefficient characteristic curve refers to the horizontal plane. 44.2 If necessary, the brightness coefficient curve in the vertical plane can also be drawn, but the vertical angle is only 20 degrees above and below. The method is the same as above. When measuring, the plane of the sample is rotated 90 degrees. To distinguish, the words "in the vertical plane" should be added in the title of the curve. 5 Determination of the brightness coefficient β and the effective angle of reflection 2a of the transmission screen H
5.1 Measurement will be heavy
JB/T 83892001
Except the second half of 4.1.1 is changed to "the size of the test room should not be less than 6m×5m", the rest are the same as 4.15.2 Measurement
Except the addition of "place the missing beam away from the light outside the silver solution sample (additional shielding)", the rest are 4.25.3 Measurement
5.3.1 Under the micro-foot recording of 5.2, as shown in Figure 3: When holding the silver sample, it should be close to the frame light hole plane, with Project light toward the non-viewing surface. Place a reflective standard plate with a known brightness coefficient at the center of the non-viewing surface of the screen sample and bring it close to the center parallel to it. 5.3.2 Turn on the collecting device and heat it. Place a meter at a 5-degree angle to the normal line of the center of the screen sample on a water plane passing through the center of the screen sample. Then measure the reflection brightness of the standard plate. The transmission coefficient test result (horizontal plane) is shown in Figure 3. 5.3.3 Send the diffuse reflection standard plate to the sample, move the brightness meter to the screen for viewing, the distance and measurement are consistent, the brightness meter objective lens optical axis should be perpendicular to the surface of the sample and pass through its center, that is, at the viewing angle of 0, calculate the brightness coefficient of the sample using formula (2), and calculate it to the second decimal place: 5.3.5 After the required value is 1, the effective angle 2 should be measured immediately. As shown in Figure 4, place the brightness meter on a horizontal plane and the equal distance arc inside. The method of observing the silver difference is to gradually increase the observation while avoiding the decrease of the brightness, and the change reading drops to 1/2 of the value, and the angle between the viewing line and the center of the sample is 1/2. When the left and right sides are symmetrical, the second angle is the effective micro-reflection angle of the sample. a constant plate is accurate to 0.5°.
Fast and accurate
Figure 4 Schematic diagram of effective micro-reflection angle 24 measurement of transmission (in the horizontal plane) Brightness meter
JB/T 8389—2001
When the viewing angle of the luminance meter increases to %, its reading is greater than 1 of L, and the viewing angle does not increase. The conclusion is that the effective scattering angle is above 160
on both sides. When the value is not correct, the first step should be to find the reason for the asymmetry, such as the projection is not plumb, the projection axis and the object are not perpendicular. When the test conditions are correct and the cutout is still asymmetric, the smaller value should be taken as the effective scattering angle. 5.4 Transmission brightness coefficient characteristic curve
5.4.1 When necessary, the brightness coefficient characteristic curve within the 50 viewing angle range of the horizontal plane can be drawn. The principle and curve drawing method are the same as 4.4.i.
5.4.2 Screen. The brightness coefficient characteristic curve in the vertical plane can also be drawn. The measurement principle, method and curve drawing method are the same as 4.4.2. 6 Determination of the comprehensive index
According to the detailed information of the silver under test The measured value of the effective receiving angle 20 of the product is based on the corresponding table in Table 1-Table 3 of the sound attenuation/T70092DD0. If it is within the allowable range, the corresponding P2a can be found out, and then the effective value can be added according to the value definition; if one of the actual values is not within the range specified in Table 1 and Table 8, the base value is judged to be 0
for the measurement of sound attenuation (only applicable to the reflection drop of the hole) 7.1 Filter installation implementation
7.1.1 A signal generator that can produce normal wave output, and its frequency range should be not less than 500H2-12500H. 7.1.2 A loudspeaker with a diameter of not less than 76N and not more than 152N; 7.1.3 A power meter for measuring the input of the filter; 7.1.4 A sound level meter for measuring the maximum sound pressure;
71.5 A small frame for setting the screen sample vertically. 7.2 Measurement conditions 7.2.1 The test room should be composed of two adjacent rooms. There should be two test holes between the two rooms. The difference in area and shape between the two rooms should not exceed 105. The volume of each room should be greater than 5m2. The indoor environment should meet the free sound field conditions, that is, the difference between the pressure measured in the air 0.5m in front of the horizontal front of the lift port and the pressure measured by the reservoir should be within 46. The ambient noise should be at least 10R lower than the pressure measured by the sound level at various frequencies. 7.2.2 The sample area to be tested should be no less than 2r×2m. The position relationship of all equipment and components is shown in Figure 5. Figure 5 shows the main points. 7.3 Measurement steps 8389—2001
7.3.1 As shown in Figure 5, place the recorder and the sound level meter on the same horizontal axis, 25 meters from the floor. The distance between the two is 2 meters. The sound level meter needs to be more accurate:
7.3.2 Sine wave signals of 500Hz and 8000Hz (2500Hz frequency) are respectively input into the sound recorder at a fixed frequency. At this time, the sound pressure readings of these three frequencies on the sound level meter are measured. 7.33 The vertical test sample is shown in Figure 5. The vertical test sample is placed in front of the high-frequency device and the square hole is placed on the plane of the test sample. Under the above conditions, the pressure readings of the sound level meter are recorded at three frequencies: 500Hz, 0Hz and 13500Hz. 7.3.4 First calculate the values before and after the three frequencies are calculated, and then calculate the values of 8000Hz and 12500Hz and the values of 500Hz and 13500Hz respectively. H attenuation difference, the silver needs to be produced in the reduction channel. 7.3.5 When it is necessary, the identification of the commonly used frequency in the range of 500Hz-12500Hz: 500Hz63Ex,800[z.100Hz,1250 z,1600Hz,2000Hz2500Hx,3150H>,4000Hz,5000Hz,6300H,8000Hz.10000112500H of the business, can be a case of sound through the characteristic curve.
JB/T8389.-2001
[Appendix]
shell coefficient characteristic curve surface method diagram
41 polar coordinate drawing method as shown in Figure 1; angle dust method as shown in Figure 42. Figure AI
level coordinates
Figure 2 right angle semi-standard3. The brightness coefficient is calculated by the method of the appendix. The brightness coefficient characteristic curve is drawn by measuring every 5 points and then calculating the value of the coefficient at 2 points on the product side. By comparison, only the measurement method can be used to measure every 5 points on one side, and the full-line graph can be drawn symmetrically. The brightness coefficient characteristic curve can be drawn by rectangular coordinates: there are two types of surface curves: rectangular coordinates and rectangular coordinates. Due to its characteristics, rectangular coordinates are required to draw the curve, and the expression is also completely super. Without any explanation, the brightness coefficient characteristic curve refers to the horizontal plane. 44.2 If necessary, the brightness coefficient characteristic curve in the vertical plane can also be drawn, but the vertical angle is only taken at 20 degrees above and below. The method is the same as above, and the sample plane is rotated 90 degrees when measuring. To distinguish, the words "in the vertical plane\" should be added in the title of the curve graph. 5 Determination of the brightness coefficient β and effective angle of incidence 2a of the transmitted screen H
5.1 Measurement will be repeated
JB/T 83892001
Except that the second half of 4.1.1 is changed to "the size of the test room should not be less than 6m×5m\", the rest are the same as 4.15.2 Measurement
Except that 4.2.5 should be supplemented with "the light beam outside the silver solution sample needs to be shielded (accumulated cloth), the rest of the room 4.25.3 MeasurementwwW.bzxz.Net
5.3.1 Under the recording of micro-foot 5.2, as shown in Figure 3: When holding the silver sample, it should be close to the plane of the frame aperture, with Project light toward the non-viewing surface. Place a reflective standard plate with a known brightness coefficient at the center of the non-viewing surface of the screen sample and bring it close to the center parallel to it. 5.3.2 Turn on the collecting device and heat it. Place a meter at a 5-degree angle to the normal line of the center of the screen sample on a water plane passing through the center of the screen sample. Then measure the reflection brightness of the standard plate. The transmission coefficient test result (horizontal plane) is shown in Figure 3. 5.3.3 Send the diffuse reflection standard plate to the sample, move the brightness meter to the screen for viewing, the distance and measurement are consistent, the brightness meter objective lens optical axis should be perpendicular to the surface of the sample and pass through its center, that is, at the viewing angle of 0, calculate the brightness coefficient of the sample using formula (2), and calculate it to the second decimal place: 5.3.5 After the required value is 1, the effective angle 2 should be measured immediately. As shown in Figure 4, place the brightness meter on a horizontal plane and the equal distance arc inside. The method of observation is to gradually increase the brightness while avoiding the change of the brightness, and the change reading drops to 1/2 of the value of L. When the angle between the viewing line and the center of the sample is 1/2, the angle between the viewing line and the center of the sample is 1/2. When the left and right sides are symmetrical, the angle between the viewing line and the center of the sample is the effective micro-reflection angle of the sample. a constant plate is accurate to 0.5°.
Fast and accurate operation
Figure 4 Schematic diagram of effective micro-reflection angle measurement (in the horizontal plane) Brightness meter
JB/T 8389—2001
When the viewing angle of the luminance meter increases to %, its reading is greater than 1 of L, and the viewing angle does not increase. The conclusion is that the effective scattering angle is above 160
on both sides. When the value is not correct, the first step should be to find the cause of the asymmetry, such as the projection is not plumb, the projection axis and the object are not perpendicular. When the test conditions are correct and the cutout is still asymmetric, the smaller value should be taken as the effective scattering angle. 5.4 Transmission brightness coefficient characteristic curve
5.4.1 When necessary, the brightness coefficient characteristic curve within the 50 viewing angle range of the horizontal plane can be drawn. The principle and curve drawing method are the same as 4.4.i.
5.4.2 Screen. The brightness coefficient characteristic curve in the vertical plane can also be drawn. The measurement principle, method and curve drawing method are the same as 4.4.2. 6 Determination of the comprehensive index
According to the detailed information of the silver under test The measured value of the effective receiving angle 20 of the product is based on the corresponding table in Table 1-Table 3 of the sound attenuation/T70092DD0. If it is within the allowable range, the corresponding P2a can be found out, and then the effective value can be added according to the value definition; if one of the actual values is not within the range specified in Table 1 and Table 8, the base value is judged to be 0
for the measurement of sound attenuation (only applicable to the reflection drop of the hole) 7.1 Filter installation implementation
7.1.1 A signal generator that can produce normal wave output, and its frequency range should be not less than 500H2-12500H. 7.1.2 A loudspeaker with a diameter of not less than 76N and not more than 152N; 7.1.3 A power meter for measuring the input of the filter; 7.1.4 A sound level meter for measuring the maximum sound pressure;
71.5 A frame for a small vertically mounted sample screen. 7.2 Measurement conditions 7.2.1 The test room should be composed of two adjacent rooms. There should be two test holes between the two rooms. The difference in area and shape between the two rooms should not exceed 105. The volume of each room should be greater than 5m2. The indoor environment should meet the free sound field conditions, that is, the difference between the pressure measured in the air 0.5m in front of the horizontal front of the lift port and the pressure measured by the reservoir should be within 46. The ambient noise should be at least 10R lower than the pressure measured by the sound level at various frequencies. 7.2.2 The sample area to be tested should be no less than 2r×2m. The position relationship of all equipment and components is shown in Figure 5. Figure 5 shows the main points of the test. 7.3 Measurement steps 8389—2001
7.3.1 As shown in Figure 5, place the recorder and the sound level meter on the same horizontal axis, 25 meters from the floor. The distance between the two is 2 meters. The sound level meter needs to be more accurate:
7.3.2 Sine wave signals of 500Hz and 8000Hz (2500Hz frequency) are respectively input into the sound recorder at a fixed frequency. At this time, the sound pressure readings of these three frequencies on the sound level meter are measured. 7.33 The vertical test sample is shown in Figure 5. The vertical test sample is placed in front of the high-frequency device and the square hole is placed on the plane of the test sample. Under the above conditions, the pressure readings of the sound level meter are recorded at three frequencies: 500Hz, 0Hz and 13500Hz. 7.3.4 First calculate the values before and after the three frequencies are calculated, and then calculate the values of 8000Hz and 12500Hz and the values of 500Hz and 13500Hz respectively. H attenuation difference, the silver needs to be produced in the reduction channel. 7.3.5 When it is necessary, the identification of the commonly used frequency in the range of 500Hz-12500Hz: 500Hz63Ex,800[z.100Hz,1250 z,1600Hz,2000Hz2500Hx,3150H>,4000Hz,5000Hz,6300H,8000Hz.10000112500H of the business, can be a case of sound through the characteristic curve.
JB/T8389.-2001
[Appendix]
Shell coefficient characteristic curve surface method diagram
41 Polar coordinate drawing method as shown in Figure 1; Angle dust method as shown in Figure 42. Figure AI
Level coordinates
Figure 2 Rectangular semi-standard3. The brightness coefficient is calculated by the method of the appendix. The brightness coefficient characteristic curve is drawn by measuring every 5 points and then calculating the value of the coefficient at 2 points on the product side. By comparison, only the measurement method can be used to measure every 5 points on one side, and the full-line graph can be drawn symmetrically. The brightness coefficient characteristic curve can be drawn by rectangular coordinates: there are two types of surface curves: rectangular coordinates and rectangular coordinates. Due to its characteristics, rectangular coordinates are required to draw the curve, and the expression is also completely super. Without any explanation, the brightness coefficient characteristic curve refers to the horizontal plane. 44.2 If necessary, the brightness coefficient characteristic curve in the vertical plane can also be drawn, but the vertical angle is only taken at 20 degrees above and below. The method is the same as above, and the sample plane is rotated 90 degrees when measuring. To distinguish, the words "in the vertical plane\" should be added in the title of the curve graph. 5 Determination of the brightness coefficient β and effective angle of incidence 2a of the transmitted screen H
5.1 Measurement will be repeated
JB/T 83892001
Except that the second half of 4.1.1 is changed to "the size of the test room should not be less than 6m×5m\", the rest are the same as 4.15.2 Measurement
Except that 4.2.5 should be supplemented with "the light beam outside the silver solution sample needs to be shielded (accumulated cloth), the rest of the room 4.25.3 Measurement
5.3.1 Under the recording of micro-foot 5.2, as shown in Figure 3: When holding the silver sample, it should be close to the plane of the frame aperture, with Project light toward the non-viewing surface. Place a reflective standard plate with a known brightness coefficient at the center of the non-viewing surface of the screen sample and bring it close to the center parallel to it. 5.3.2 Turn on the collecting device and heat it. Place a meter at a 5-degree angle to the normal line of the center of the screen sample on a water plane passing through the center of the screen sample. Then measure the reflection brightness of the standard plate. The transmission coefficient test result (horizontal plane) is shown in Figure 3. 5.3.3 Send the diffuse reflection standard plate to the sample, move the brightness meter to the screen for viewing, the distance and measurement are consistent, the brightness meter objective lens optical axis should be perpendicular to the surface of the sample and pass through its center, that is, at the viewing angle of 0, calculate the brightness coefficient of the sample using formula (2), and calculate it to the second decimal place: 5.3.5 After the required value is 1, the effective angle 2 should be measured immediately. As shown in Figure 4, place the brightness meter on a horizontal plane and the equal distance arc inside. The method of observation is to gradually increase the brightness while avoiding the change of the brightness, and the change reading drops to 1/2 of the value of L. When the angle between the viewing line and the center of the sample is 1/2, the angle between the viewing line and the center of the sample is 1/2. When the left and right sides are symmetrical, the angle between the viewing line and the center of the sample is the effective micro-reflection angle of the sample. a constant plate is accurate to 0.5°.
Fast and accurate operation
Figure 4 Schematic diagram of effective micro-reflection angle measurement (in the horizontal plane) Brightness meter
JB/T 8389—2001
When the viewing angle of the luminance meter increases to %, its reading is greater than 1 of L, and the viewing angle does not increase. The conclusion is that the effective scattering angle is above 160
on both sides. When the value is not correct, the first step should be to find the cause of the asymmetry, such as the projection is not plumb, the projection axis and the object are not perpendicular. When the test conditions are correct and the cutout is still asymmetric, the smaller value should be taken as the effective scattering angle. 5.4 Transmission brightness coefficient characteristic curve
5.4.1 When necessary, the brightness coefficient characteristic curve within the 50 viewing angle range of the horizontal plane can be drawn. The principle and curve drawing method are the same as 4.4.i.
5.4.2 Screen. The brightness coefficient characteristic curve in the vertical plane can also be drawn. The measurement principle, method and curve drawing method are the same as 4.4.2. 6 Determination of the comprehensive index
According to the detailed information of the silver under test The measured value of the effective receiving angle 20 of the product is based on the corresponding table in Table 1-Table 3 of the sound attenuation/T70092DD0. If it is within the allowable range, the corresponding P2a can be found out, and then the effective value can be added according to the value definition; if one of the actual values is not within the range specified in Table 1 and Table 8, the base value is judged to be 0
for the measurement of sound attenuation (only applicable to the reflection drop of the hole) 7.1 Filter installation implementation
7.1.1 A signal generator that can produce normal wave output, and its frequency range should be not less than 500H2-12500H. 7.1.2 A loudspeaker with a diameter of not less than 76N and not more than 152N; 7.1.3 A power meter for measuring the input of the filter; 7.1.4 A sound level meter for measuring the maximum sound pressure;
71.5 A frame for a small vertically mounted sample screen. 7.2 Measurement conditions 7.2.1 The test room should be composed of two adjacent rooms. There should be two test holes between the two rooms. The difference in area and shape between the two rooms should not exceed 105. The volume of each room should be greater than 5m2. The indoor environment should meet the free sound field conditions, that is, the difference between the pressure measured in the air 0.5m in front of the horizontal front of the lift port and the pressure measured by the reservoir should be within 46. The ambient noise should be at least 10R lower than the pressure measured by the sound level at various frequencies. 7.2.2 The sample area to be tested should be no less than 2r×2m. The position relationship of all equipment and components is shown in Figure 5. Figure 5 shows the main points of the test. 7.3 Measurement steps 8389—2001
7.3.1 As shown in Figure 5, place the recorder and the sound level meter on the same horizontal axis, 25 meters from the floor. The distance between the two is 2 meters. The sound level meter needs to be more accurate:
7.3.2 Sine wave signals of 500Hz and 8000Hz (2500Hz frequency) are respectively input into the sound recorder at a fixed frequency. At this time, the sound pressure readings of these three frequencies on the sound level meter are measured. 7.33 The vertical test sample is shown in Figure 5. The vertical test sample is placed in front of the high-frequency device and the square hole is placed on the plane of the test sample. Under the above conditions, the pressure readings of the sound level meter are recorded at three frequencies: 500Hz, 0Hz and 13500Hz. 7.3.4 First calculate the values before and after the three frequencies are calculated, and then calculate the values of 8000Hz and 12500Hz and the values of 500Hz and 13500Hz respectively. H attenuation difference, the silver needs to be produced in the reduction channel. 7.3.5 When it is necessary, the identification of the commonly used frequency in the range of 500Hz-12500Hz: 500Hz63Ex,800[z.100Hz,1250 z,1600Hz,2000Hz2500Hx,3150H>,4000Hz,5000Hz,6300H,8000Hz.10000112500H of the business, can be a case of sound through the characteristic curve.
JB/T8389.-2001
[Appendix]
Shell coefficient characteristic curve surface method diagram
41 Polar coordinate drawing method as shown in Figure 1; Angle dust method as shown in Figure 42. Figure AI
Level coordinates
Figure 2 Rectangular semi-standard5 After the required value is 1, the effective angle of incidence 2 should be measured immediately. As shown in Figure 4, the brightness meter is placed on the horizontal plane and the equidistant arc is gradually increased while the brightness is reduced. The reading decreases to L. When the value is 1/2 of the value, the viewing angle between the meter and the center of the sample is 1/2, and when the left and right sides are symmetrical, the second angle is the effective angle of incidence of the sample. The accuracy is 0.5°. Figure 4 Schematic diagram of effective micro-angle measurement of transmission (in the horizontal plane) Brightness meter JB/T 8389—2001 When the viewing angle of the brightness meter increases to %, the reading is greater than L. When the viewing angle does not increase, the reading does not decrease. The conclusion is that the effective angle of incidence is above 160°. When the value is not correct, the first step is to find the reason for the asymmetry, such as the projection is not plumb, the projection axis is not perpendicular to the object, and when the test conditions are correct but the cutout is still asymmetric, the smaller value of the two grids should be taken as the effective scattering angle. 5.4 Transmission brightness coefficient characteristic curve
5.4.1 When necessary, the brightness coefficient characteristic curve within the horizontal plane 50° observation angle range can be made. The principle and curve drawing method are the same as 4.4.i.
5.4.2 If necessary, the brightness coefficient characteristic curve within the vertical plane can also be made. The determination principle, method and curve drawing method are the same as 4.4.2. 6 Determination of comprehensive index
According to the actual measured value of the brightness of the tested silver product, according to the corresponding table in Table 1-Table 3 of the display type, if it is within the allowable range, the corresponding P2a can be found out, and then according to Definition of value: Herein refers to the effective value; if one of the actual values is not within the range values specified in Table 1 and Table 8, the judgment base value is 0. Determination of sound attenuation (only applicable to hole reflection drop) 7.1 Filter installation 7.1.1 A signal transmitter that can produce a normal wave output, and its frequency range should be not less than 500H2-12500H. 7.1.2 A loudspeaker with a diameter of not less than 76N and not more than 152N; 7.1.3 A power meter for measuring the input of the service device; 7.1.4 A sound level meter for measuring the maximum sound pressure; 7.1.5 A small frame for vertically setting the screen sample. 7.2 Measurement conditions 7.2.1 The test room should be composed of two adjacent rooms. There should be two test holes between the two rooms. The difference in area and shape between the two rooms should not exceed 105. The volume of each room should be greater than 5m2. The indoor environment should meet the free sound field conditions, that is, the difference between the pressure measured in the air 0.5m in front of the horizontal front of the lift port and the pressure measured by the reservoir should be within 46. The ambient noise should be at least 10R lower than the pressure measured by the sound level at various frequencies. 7.2.2 The sample area to be tested should be no less than 2r×2m. The position relationship of all equipment and components is shown in Figure 5. Figure 5 shows the main points. 7.3 Measurement steps 8389—2001
7.3.1 As shown in Figure 5, place the recorder and the sound level meter on the same horizontal axis, 25 meters from the floor. The distance between the two is 2 meters. The sound level meter needs to be more accurate:
7.3.2 Sine wave signals of 500Hz and 8000Hz (2500Hz frequency) are respectively input into the sound recorder at a fixed frequency. At this time, the sound pressure readings of these three frequencies on the sound level meter are measured. 7.33 The vertical test sample is shown in Figure 5. The vertical test sample is placed in front of the high-frequency device and the square hole is placed on the plane of the test sample. Under the above conditions, the readings of the sound level meter at three frequencies of 500Hz, 0Hz and 13500Hz are obtained. 7.3.4 First calculate the values before and after the three frequencies, and then calculate the values of 8000Hz and 12500Hz and 500Hz. H attenuation difference, the silver needs to be produced in the reduction channel. 7.3.5 When it is necessary, the identification of the commonly used frequency in the range of 500Hz-12500Hz: 500Hz63Ex,800[z.100Hz,1250 z,1600Hz,2000Hz2500Hx,3150H>,4000Hz,5000Hz,6300H,8000Hz.10000112500H of the business, can be a case of sound through the characteristic curve.
JB/T8389.-2001
[Appendix]
shell coefficient characteristic curve surface method diagram
41 polar coordinate drawing method as shown in Figure 1; angle dust method as shown in Figure 42. Figure AI
level coordinates
Figure 2 right angle semi-standard5 After the required value is 1, the effective angle of incidence 2 should be measured immediately. As shown in Figure 4, the brightness meter is placed on the horizontal plane and the equidistant arc is gradually increased while the brightness is reduced. The reading decreases to L. When the value is 1/2 of the value, the viewing angle between the meter and the center of the sample is 1/2, and when the left and right sides are symmetrical, the second angle is the effective angle of incidence of the sample. The accuracy is 0.5°. Figure 4 Schematic diagram of effective micro-angle measurement of transmission (in the horizontal plane) Brightness meter JB/T 8389—2001 When the viewing angle of the brightness meter increases to %, the reading is greater than L. When the viewing angle does not increase, the reading does not decrease. The conclusion is that the effective angle of incidence is above 160°. When the value is not correct, the first step is to find the reason for the asymmetry, such as the projection is not plumb, the projection axis is not perpendicular to the object, and when the test conditions are correct but the cutout is still asymmetric, the smaller value of the two grids should be taken as the effective scattering angle. 5.4 Transmission brightness coefficient characteristic curve
5.4.1 When necessary, the brightness coefficient characteristic curve within the horizontal plane 50° observation angle range can be made. The principle and curve drawing method are the same as 4.4.i.
5.4.2 If necessary, the brightness coefficient characteristic curve within the vertical plane can also be made. The determination principle, method and curve drawing method are the same as 4.4.2. 6 Determination of comprehensive index
According to the actual measured value of the brightness of the tested silver product, according to the corresponding table in Table 1-Table 3 of the display type, if it is within the allowable range, the corresponding P2a can be found out, and then according to Definition of value: Herein refers to the effective value; if one of the actual values is not within the range values specified in Table 1 and Table 8, the judgment base value is 0. Determination of sound attenuation (only applicable to hole reflection drop) 7.1 Filter installation 7.1.1 A signal transmitter that can produce a normal wave output, and its frequency range should be not less than 500H2-12500H. 7.1.2 A loudspeaker with a diameter of not less than 76N and not more than 152N; 7.1.3 A power meter for measuring the input of the service device; 7.1.4 A sound level meter for measuring the maximum sound pressure; 7.1.5 A small frame for vertically setting the screen sample. 7.2 Measurement conditions 7.2.1 The test room should be composed of two adjacent rooms. There should be two test holes between the two rooms. The difference in area and shape between the two rooms should not exceed 105. The volume of each room should be greater than 5m2. The indoor environment should meet the free sound field conditions, that is, the difference between the pressure measured in the air 0.5m in front of the horizontal front of the lift port and the pressure measured by the reservoir should be within 46. The ambient noise should be at least 10R lower than the pressure measured by the sound level at various frequencies. 7.2.2 The sample area to be tested should be no less than 2r×2m. The position relationship of all equipment and components is shown in Figure 5. Figure 5 shows the main points. 7.3 Measurement steps 8389—2001
7.3.1 As shown in Figure 5, place the recorder and the sound level meter on the same horizontal axis, 25 meters from the floor. The distance between the two is 2 meters. The sound level meter needs to be more accurate:
7.3.2 Sine wave signals of 500Hz and 8000Hz (2500Hz frequency) are respectively input into the sound recorder at a fixed frequency. At this time, the sound pressure readings of these three frequencies on the sound level meter are measured. 7.33 The vertical test sample is shown in Figure 5. The vertical test sample is placed in front of the high-frequency device and the square hole is placed on the plane of the test sample. Under the above conditions, the pressure readings of the sound level meter are recorded at three frequencies: 500Hz, 0Hz and 13500Hz. 7.3.4 First calculate the values before and after the three frequencies are calculated, and then calculate the values of 8000Hz and 12500Hz and the values of 500Hz and 13500Hz respectively. H attenuation difference, the silver needs to be produced in the reduction channel. 7.3.5 When it is necessary, the identification of the commonly used frequency in the range of 500Hz-12500Hz: 500Hz63Ex,800[z.100Hz,1250 z,1600Hz,2000Hz2500Hx,3150H>,4000Hz,5000Hz,6300H,8000Hz.10000112500H of the business, can be a case of sound through the characteristic curve.
JB/T8389.-2001
[Appendix]
Shell coefficient characteristic curve surface method diagram
41 Polar coordinate drawing method as shown in Figure 1; Angle dust method as shown in Figure 42. Figure AI
Level coordinates
Figure 2 Rectangular semi-standard3150H>, 4000Hz, 5000Hz, 6300H, 8000Hz.10000112500H, can be three sound through the characteristic curve.
JB/T8389.-2001
[Appendix]
Shell coefficient characteristic curve surface method diagram
41 Polar coordinate drawing method is shown in Figure 1; Angle dust is shown in Figure 42. Figure AI
Level coordinates
Figure 2 Rectangular semi-standard3150H>, 4000Hz, 5000Hz, 6300H, 8000Hz.10000112500H, can be three sound through the characteristic curve.
JB/T8389.-2001
[Appendix]
Shell coefficient characteristic curve surface method diagram
41 Polar coordinate drawing method is shown in Figure 1; Angle dust is shown in Figure 42. Figure AI
Level coordinates
Figure 2 Rectangular semi-standard
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