The procedure for obtaining the CNAS CMA report required for LED display screen bidding is as follows:
1. Pre-Application Preparation - Clarify the testing items, determine the specific parameters and indicators required for the tests. - Prepare the required number of samples that meet the standards.
2. Select a Testing Institution - Understand institutions with CNAS and CMA qualifications. - Compare services, prices, and reputations among different institutions.
3. Processing Procedure -- Send product images and manuals for a quote. -- Sign the contract and make the payment after confirming the quote. -- Send samples to the testing laboratory. -- Wait for the test and confirm the electronic draft. -- Issue the formal test report upon confirmation.
IV. Standard Basis of the Report - Introduce applicable national standards, industry standards, local standards, corporate standards, or product technical specifications.
LED Display Performance Testing Standards:
SJ/T 11141-2017 General Specification for Light Emitting Diode (LED) Display Screens
SJ/T 11281-2017 Test Methods for Light Emitting Diode (LED) Display Screens
SJ/T 11590-2016 Method for Subjective Evaluation of LED Display Image Quality
GB 4943.1-2022 Audio, Video, Information Technology, and Communication Technology Equipment — Part 1: Safety Requirements
GB 21520-2015 Energy Efficiency Limit Values and Energy Efficiency Grades for Computer Monitors
GB/T 4208-2017 Ingress Protection (IP) Code for Enclosures
GB/T 20145-2006 Light and Lighting Systems - Photobiological Safety
V. Inspection Items and Functions - List common inspection items such as resolution and brightness. - Explain the main functions and roles of the inspection report.
LED Display Inspection Items Reference:
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Base color dominant wavelength Tolerance
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2
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Uniform brightness
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3
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Color uniformity
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4
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Viewable Angle
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5
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Contrast
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6
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Pixel failure rate
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7
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Brightness
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8
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Luminosity Grade
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9
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Color Temperature
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10
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Frame Rate
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11
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Refresh Rate
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12
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Gray scale levels
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13
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Signal Processing Depth
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14
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Brightness Discrimination Grade
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15
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White field color coordinates
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VI. Cost-Related Information - Explain the methods of cost evaluation and factors affecting it. - Provide a general cost range for reference.
Section 7: Cautionary Notes - Emphasize the authenticity and validity of the inspection report. - Remind of the proper use of the original and copies of the report.
