GB/T 7974-2013 "Paper, board and pulps — Measurement of diffuse blue reflectance factor (D65 brightness)" specifies the method for determining the diffuse blue reflectance factor (D65 brightness) of paper, board, and pulps using the diffuse/vertical method, applicable to all types of paper, board, and pulps. The method employs the D65 standard illuminant and the 10° standard observer, with barium sulfate whiteboard as the reference. It details instrument calibration, specimen preparation, and testing conditions. Specimens must be conditioned under standard temperature and humidity, with at least four measurement points per specimen, and the average value is taken as the result to ensure accurate and consistent brightness measurement.
This summary is not the original standard text and is for reference only. For accurate information, please obtain it through official channels.
| Status | Active | ||
|---|---|---|---|
| CCS | Y30 | ICS | 85.010 |
| Release Date | 2013-10-10 00:00:00 | Implementation Date | 2014-05-01 00:00:00 |