GB/T 39492-2020 PDF EnglishUS$110.00 · In stock · Download in 9 seconds
GB/T 39492-2020: Testing method of quantum efficiency for white LED phosphor Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid
Similar standardsGB/T 39492-2020: Testing method of quantum efficiency for white LED phosphor---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GBT39492-2020GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 77.120.99 H 14 Testing Method of Quantum Efficiency for White LED Phosphor Issued on: NOVEMBER 19, 2020 Implemented on: OCTOBER 1, 2021 Issued by. State Administration for Market Regulation; Standardization Administration of the People’s Republic of China. Table of ContentsForeword... 3 1 Scope... 4 2 Normative References... 4 3 Terms and Definitions... 4 4 Method Principles... 5 5 Instruments and Devices... 5 6 Test Procedures... 6 7 Expression of Test Results... 7 8 Precision... 7 9 Requirements for Test Report... 8 Testing Method of Quantum Efficiency for White LED Phosphor1 ScopeThis Standard specifies the method principles, instruments and devices, test procedures, test result expression, precision and test report requirements for the quantum efficiency of phosphors used for white LEDs. This Standard is applicable to the testing of the external quantum efficiency and internal quantum efficiency of white LED phosphor emitting in the band range of 400 nm ~ 780 nm when the LED chip is excited with a peak wavelength of 400 nm ~ 480 nm. The determination range of external quantum efficiency is 0.6 ~ 0.9, and the determination range of internal quantum efficiency is greater than 0.9.2 Normative ReferencesThe following documents are indispensable to the application of this document. In terms of references with a specified date, only versions with a specified date are applicable to this document. In terms of references without a specified date, the latest version (including all the modifications) is applicable to this document. GB/T 8170 Rules of Rounding off for Numerical Values & Expression and Judgement of Limiting Values3 Terms and DefinitionsThe following terms and definitions are applicable to this document. 3.1 external quantum efficiency The ratio of the total number of photons corresponding to the fluorescence emitted by a luminescent material when excited to the total number of photons irradiated onto the phosphor sample during excitation, which is used to determine the conversion efficiency of phosphor to the incident light source. 3.2 internal quantum efficiency The ratio of the total number of photons corresponding to the fluorescence emitted by a luminescent material when excited to the total number of photons absorbed when excited, which is used to determine the conversion efficiency of phosphor to the absorbed light source. 3.3 sample cell D---detection system; S---sample system; H1---heating system; H2---heating control system. NOTE 1.the light source system consists of an excitation light source and an excitation monochromator. NOTE 2.the sample system consists of an integrating sphere and a sample cell. NOTE 3.the detection system consists of a spectroscope, a detector, an amplifier and a signal processing unit. The detection system separates the signals required for testing, realizes the conversion between optical signals and electrical signals, and converts the light intensity of each measurement wavelength into the number of photons to perform data processing. NOTE 4.the heating system consists of a heating unit and a heating control unit. Figure 1 -- Example of Quantum Efficiency Testing Device6 Test Procedures6.1 Sample Preparation Put an appropriate amount of blank sample or powder to be tested into the sample cell, use a flat glass to flatten and compact the sample, and use a cover glass and cap to cover the sample plate. It is required that after each loading of sample, the luminescence test surface of the sample shall be flat and highly uniform. 6.2 Test 6.2.1 Turn on the equipment system and pre-heat for 30 minutes. 6.2.2 Place the sample cell or white diffuser containing the blank sample on the sample holder, use the set excitation light to irradiate it, and carry out the test to obtain the total number of light quanta (La) from the excitation source reaching the sample, and the number of background light quanta (Ea) in the fluorescence band. When using the white diffuser, the same cover glass must be placed on the sample. When using the sample cell, the blank sample and the powder to be tested must use the sample cell and cap of the same specifications. 6.2.3 Place the sample plate to be tested on the sample holder, use the same excitation light to excite it, and click TEST to obtain the data of the total number of light quanta (Lc) of the remaining excitation light after absorption by the sample under test and the number of light quanta (Ec) of the sample phosphor (calculated in accordance with the band range of 400 nm ~ 780 nm). Carry out the measurement three times in parallel and take the arithmetic mean. ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. 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