SH/T 1499.5-1997Pure adipic acid. Determination of content of iron-2, 2'-Bipyridyl spectrophotometric method (English PDF)

3.1 LED displays

A device for displaying text, image, video and other information with LED pixels, usually including basic components such as LED panel and display control system; it may also include support system and so on. It may adopt one-piece or split structure.

3.2 LED panel

It is spliced by one or several display modules. It may be controlled by the display control system to complete the screen display.

3.3 display control system

It is usually composed of a video processor, signal conditioning transmitter, signal receiving distributor and related playback control display software and so on. It may also include various signal sources and matrix switchers.

3.4 support system

Supporting equipment for the LED display. It usually includes power supply and distribution system, audio system, temperature regulation system, lightning protection system and security system.

3.5 gray scale

The maximum brightness level of any primary color of the LED display from the darkest to the brightest.

3.6 pixel

The smallest imaging unit of the LED display.

4.1 Use environment

The LED displays are divided into indoor LED displays and outdoor LED displays according to the use environment.

4.2 Display color

The LED displays are divided into single color, multi-color, and full-color LED displays according to the display color.

4.3 Display function

According to the display function, LED displays are divided into text LED display, graphic LED display, video LED display and special application LED display.

4.4 Display dimensions

The LED display can be divided into 2D display and stereo (3D) display according to display dimensions.

4.5 Panel appearance state

The LED displays are divided into planar and non-planar types according to the appearance of panel.

4.6 Pixel pitch

According to the pixel pitch, the LED display is divided into common pitch and small pitch.

5.1 Design and structure

5.1.1 Hardware

When designing LED displays, it shall perform designs on safety, electromagnetic compatibility, reliability, maintainability, ease of use, environmental adaptability and energy-saving.

5.1.4 Packaging materials

In packaging design, priority shall be given to materials that meet environmental protection requirements for packaging and cushioning materials.

5.2 Hardware environment

The LED display hardware part includes the LED panel, display control system, auxiliary system and so on. When applicable, the detailed specification shall be explained according to the classification of the LED display.

5.3 Software environment

For the LED display with different functions, it can be equipped with the display software that can meet its display function requirements.

5.4 Appearance quality

The external surface of the LED display shall have no obvious scratches. The installation of the LED display assembly shall be consistent, without looseness and crack.

5.5 Enclosure protection level

The enclosure protection level of the LED display panel is indicated by F, which shall be specified in the detailed specification. The corresponding classification registration shall be selected from Table 1.

5.6 Assembly accuracy

The assembly accuracy of the LED display shall be specified in the detailed specification. Level up degree level P, dot pitch relative deviation level JX, horizontal relative misalignment level CS and vertical relative misalignment level CC are selected from Table 2 ~ Table 5, respectively.

5.7 Safety requirements

5.7.1 General rules

The safety performance of the LED display shall meet the requirements of GB

4943.1-2011.

5.8 Energy saving

5.8.1 Average power efficiency

At room temperature, the power factor of the LED display power supply is not less than 90%, and the conversion efficiency is not less than 70%.

5.8.2 Luminance adjustment

The outdoor LED display shall have the function of automatically adjusting the luminance with the change of the environmental illumination.

5.9 Functional characteristics of LED display

5.10 Optical characteristics

5.10.1 Maximum luminance

The maximum luminance of the LED display assembly and the LED display shall comply with the detailed specification.

5.11 Electrical characteristics

5.11.1 Gray scale

The gray scale of the LED display assembly and the LED display shall meet the requirements of detailed specification.

5.14 Electromagnetic compatibility

5.15 Environmental adaptability

5.16 Mean time between failures

The average failure interval working time of the LED display, MTBF (), is not less than 5000h.

6.1 Test conditions

6.2 Structure

Visually inspect the structure of the LED display, which shall meet the requirements of 5.1.3.

6.7 Assembling accuracy

Use a universal measuring tool of which its accuracy meets 0.02mm to measure the assembling accuracy of the LED display, which shall meet the requirements of 5.6.

6.8 Safety requirements

6.8.1 General rules

The LED display that has been tested for safety shall meet relevant requirements of 5.7.1.

6.8.2 Grounding

In accordance with the provisions of GB 4943.1-2011, the grounding continuity of the LED display and the grounding resistance of the protective connecting conductor are assessed, which shall meet the requirements of 5.7.2.

6.8.3 Safety marks

Visually inspect the protective ground terminal mark and warning mark of the

LED display. And in accordance with the provisions of GB 4943.1-2011, conduct the mark durability test for the marks of the LED display, which shall meet the requirements of 5.7.3.

6.8.4 Ground leakage current

6.9 Energy saving

6.9.1 Average power efficiency

Test the average efficiency of the power supply of the LED display according to the provisions of Annex A of GB 20943-2013, which shall meet the requirements of 5.8.1.

6.9.2 Luminance adjustment

The function of adjusting the luminance of the LED display with the change of the environmental illumination, is tested according to the method specified in

5.3.6 of SJ 11281-2017.

6.10 Functional characteristics of LED display

6.11 Optical performance

6.11.1 Maximum luminance

Measure the maximum luminance according to the method specified in 5.2.1 of

SJ/T 11281-2017, which shall meet the requirements of 5.10.1.

6.11.2 View angle

Measure the view angle according to the method specified in 5.2.2 of SJ/T

11281-2017, which shall meet the requirements of 5.10.2.

6.12 Electrical performance

6.13 Pixel out of control rate

Measure the out of control pixel according to the method specified in 5.3.5 of

SJ/T 11281-2017, which shall meet the requirements of 5.12.

6.14 Power supply

Use a voltmeter and other instruments to measure the power supply of the LED display. The maximum power consumption per unit display area or the total power consumption of the LED display is measured according to the detailed specification, which shall meet the requirements of 5.13.

6.15 Electromagnetic compatibility

6.16 Environmental adaptability

6.16.5 Damp heat

6.16.7 Transportation test

6.17 Mean time between failures

The inspection of average failure interval working time of the LED display, MTBF, is according to the timed fixed number censoring test program 1-2 specified in

7.1 Inspection classification

This Specification specifies the evaluation of display assembly, type inspection and delivery inspection of LED displays.

7.2 Batching rules of inspection batch

7.2.1 Composition of inspection batch of display assembly

An inspection batch used for display assembly evaluation can consist of one or several display assembly production batches that meet the following conditions.

7.2.2 Composition of inspection batch of LED display

Unless otherwise specified, an LED display inspection batch can be made up of LED displays that are manufactured using the same process and the production batch does not exceed one month.

7.3 Display assembly evaluation

7.3.1 General rules

In one of the following cases, before assembling the LED display, the display assembly used to assemble the LED display must be evaluated.

7.3.2 Evaluation items

The evaluation items and order of the display assembly shall be in accordance with the provisions of Table 13.

7.3.3 Sample extraction

The samples provided for the evaluation of the display assembly shall be taken from the display assembly inspection batch used to assemble the LED display.

7.3.4 Sampling plan

According to the normal inspection plan of GB/T 2828.1-2012, the general inspection level is II, AQL=1.5.

7.3.5 Rejection

During the evaluation process of the display assembly, if there is a well-known defect or two or more non-critical defects, the evaluation inspection batch of the display assembly shall be rejected as a nonconforming batch.

7.3.6 Resubmission

When the display assembly evaluation test is nonconforming, it is allowed to resubmit after repairing or rejecting the nonconforming product. Sampling plan and determination criteria for the nonconforming remain unchanged. If it is still nonconforming after resubmission of evaluation, it is not allowed to use this batch of display assemblies to assemble the LED display.

7.4 Type inspection

7.4.4 Sampling plan

Four sets are extracted for display assembly. One piece is extracted for LED display.

7.4.5 Rejection

In the process of type inspection, if there is one critical defect or two or more non-critical defects, the type inspection is deemed nonconforming.

7.4.6 Resubmission

When the type inspection is nonconforming, it is allowed to resubmit after repairing or rejecting the nonconforming product. The sampling plan remains the same, but one critical defect or two or more non-critical defects are not allowed.

7.5 Delivery inspection (only for LED display)

7.5.3 Sampling plan

The sampling plan for delivery inspection is 100%.

7.5.4 Rejection

Unless otherwise specified in the contract, during the delivery inspection process, if there is a critical defect or more than two non-critical defects, the delivery inspection shall be deemed nonconforming.

7.5.5 Resubmission

When the delivery inspection is nonconforming, the first resubmission is allowed after repair. The sampling plan remains unchanged. But no defects are allowed, otherwise, it shall be deemed nonconforming for the first resubmission of inspection. However, if the first resubmission is nonconforming because there is only one critical defect or two or less non-critical defects, a second resubmission after repair is allowed. No defects are allowed. If the second resubmission is still nonconforming, it shall be rejected.

8.1 General rules

The packaging, marks and storage of the LED display shall meet the requirements of SJ/T 10463-1993.

8.2 Marks

8.2.1 Product marks

The nameplate shall be installed on the appropriate position of the LED display.

The nameplate must contain the following.

8.3 Packaging

8.4 Transportation

The packaged LED display can be transported by any means of transportation (such as cars, trains, planes and other ordinary means of transportation). But the transportation process shall avoid rain, long sun, contact with corrosive gas and mechanical damage.

8.5 Storage

The storage temperature range of the LED display is -40°C~60°C. The relative humidity is not more than 80%. There is no acid, alkali and corrosive gas in the surrounding environment, and no strong mechanical vibration, shock and strong magnetic field.

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