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GB/T 24981.1-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.120.99
H 14
Replacing GB/T 24981.1-2010
Test methods of rare earth long afterglow phosphors -
Part 1: Determination of emission dominantpeak and
chromaticity coordinates
ISSUED ON: NOVEMBER 19, 2020
IMPLEMENTED ON: OCTOBER 01, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Method principle ... 4
3 Instruments and devices ... 4
4 Test procedures ... 5
5 Precision ... 6
References ... 7
Test methods of rare earth long afterglow phosphors -
Part 1: Determination of emission dominantpeak and
chromaticity coordinates
1 Scope
This Part of GB/T 24981 specifies the determination method of emission
dominantpeak and chromaticity coordinates of rare earth long afterglow
phosphors.
This Part applies to the determination of emission dominantpeak and
chromaticity coordinates of rare earth long afterglow phosphors.
2 Method principle
The sample emits visible light of 380 nm ~ 720 nm under the excitation of 365
nm ultraviolet rays; the monochromatic light signal is converted into an electrical
signal by the spectral radiation tester for spectroscopy and photoelectric
conversion; then, the electrical signal value corresponding to the light intensity
is obtained by correction of the standard lamp. Measure the entire visible light
band at a certain wavelength interval; obtain the relative emission spectral
power distribution of the sample in the entire visible light band; calculate the
chromaticity coordinates and emission dominantpeak of the light emitted by the
sample with reference to CIE 1931.
3 Instruments and devices
3.1 Spectral radiation tester
The spectral radiation tester shall meet the following conditions:
a) Wavelength accuracy: ±2 nm;
b) Accuracy of chromaticity coordinates: ±0.001;
c) Spectral range: 380 nm ~ 720 nm.
3.2 Excitation light source
The 365 nm ultraviolet low pressure mercury lamp is equipped with a color filter;
the peak transmittance of the filter shall be greater than 10%; transmittance of
380 nm ~ 720 nm shall not be greater than 0.01%; the radiation intensity stability
of 365 nm shall be better than 0.2%/10 min, otherwise, it shall be compensated.
3.3 Sample pan
The sample pan is black, with an inner diameter of 20 mm and a depth of 3 mm.
4 Test procedures
4.1 Test conditions
4.1.1 Ambient temperature: 22 °C ~ 27 °C.
4.1.2 Relative humidity: ≤70%.
4.1.3 During the measurement process, in addition to the specified excitation
light source, there shall be no stray light interference such as visible light or
ultraviolet light.
4.2 Instrument calibration
Be stable for 10 min ~ 30 min according to the requirements of the instrument.
Refer to the instrument manual to calibrate the instrument.
4.3 Test
4.3.1 Load the sample into the sample pan; compact and make the surface flat.
4.3.2 Place the sample pan in the sample chamber to be excited, so that the
sample is excited by the ultraviolet lamp.
4.3.3 Irradiate the sample under an ultraviolet lamp for more than 1 min; scan
from the 380 nm ~ 720 nm wavelength range; measure the relative spectral
power distribution of the sample and the peak wavelength of the emission
dominantpeak. The emission dominantpeak is expressed by the peak
wavelength (λ).
4.3.4 According to the measured relative spectral power distribution, calculate
the chromaticity coordinates (x, y) with reference to CIE 1931.
4.3.5 Repeat the test 3 times for a sample; take the arithmetic mean value.
......
(Above excerpt was released on 2021-09-03, modified on 2021-09-03, translated/reviewed by: Wayne Zheng et al.)
Source: https://www.chinesestandard.net/PDF.aspx/GBT24981.1-2020