GB/T 24981.2-2020 in English

Background of Standard Revision and Technological Evolution

GB/T24981.2-2020, as an important part of the series of standards for rare earth luminescent material test methods, reflects the development of phosphor detection technology in the past decade. Compared with the 2010 version, the main technological evolution is reflected in:

Key Terms Analysis

Saturation Excitation: The new standard clearly defines it as a stable state where the afterglow brightness change value is ≤5% when excited by a 5500K-6500K light source. This definition solves the problem of unclear excitation degree in the old version of the standard.

Test system configuration requirements

Key points for test process optimization

1. Pretreatment: The sample needs to be kept away from light for 24 hours to eliminate the influence of historical excitation
2. Environmental control: Temperature 22±5℃, humidity ≤70%
3. Illuminance correction: Use a standard illuminance meter to calibrate to 1000±5lx or 25±0.5lx
4. Parallel test: The relative deviation of 3 measurements is ≤5%

Implementation suggestions

1. LED excitation light source is preferred: It is recommended to use an LED array with a color temperature of 6000K±100K to ensure spectral stability

2. Test time window control: from turning off the light source to the first measurement should be controlled within 10 seconds

3. Data recording specification: it is recommended to add 5min brightness value recording to better reflect the characteristics of the attenuation curve

4. Inter-laboratory comparison: perform proficiency verification regularly to ensure the allowable difference requirement of ≤15%