GB/T 7973-2003 Paper, board and pulps - Measurement of diffuse reflectance factor (Diff/Geometry)
1 Scope
This standard specifies the basic conditions for measuring the diffuse reflectance factor of paper, board and pulps, such as the spectral, geometric, and photometric characteristics of the instruments used, as well as the methods for transferring standard values.
Measurements of diffuse reflectance factor may be used for the determination of optical properties such as the diffuse blue reflectance factor (blue brightness), color, light scattering and absorption coefficients of pulp, paper and board, as well as the opacity of paper.
This standard is applicable to the measurement of paper, board and pulps.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest edition of the normative document applies.
GB/T 450 Paper and board - Sampling for testing (GB/T 450-2002, eqv ISO 186:1994)
GB/T 740 Pulps - Sampling for testing (GB/T 740-2003, ISO 7213:1991, IDT)
GB/T 1543 Paper - Determination of opacity (paper backing) (GB/T 1543-1988, neq ISO 2471:1977)
GB/T 2679.1 Paper - Determination of transparent
GB/T 7974 Paper, board and pulp - Measurement of brightness - Diff/Geometry (GB/T 7974-2002, neq ISO 2470:1999)
GB/T 7975 Paper and board - Measurement of color (Diff/o-Geometry)
GB/T 10339 Testing method of light scattering and absorption coefficient for paper and pulps (GB/T 10339-1989, eqv ISO/DP 9416)
3 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
3.1
reflectance factor
the ratio, expressed as a percentage, of the radiant flux reflected by a body to that reflected by the perfect reflecting diffuser under the same conditions
3.2
diffuse reflectance factor, R
the ratio, expressed as a percentage, of the radiant flux reflected by a body to that reflected by the perfect reflecting diffuser under the same conditions of diffuse illumination described in this standard in an instrument calibrated in accordance with the provisions of this standard
3.3
intrinsic reflectance factor, R∞
the reflectance factor of a layer of test piece thick enough to be opaque
Contents
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Basic conditions for transferring standard values
5 Instruments
6 Sampling
7 Preparation of test pieces
8 Procedure
9 Calculation and reporting of measurement results
Annex A (Normative) Instruments for the measurement of reflectance factor
Annex B (Informative) Calibration of instruments
GB/T 7973-2003 Paper, board and pulps - Measurement of diffuse reflectance factor (Diff/Geometry)
1 Scope
This standard specifies the basic conditions for measuring the diffuse reflectance factor of paper, board and pulps, such as the spectral, geometric, and photometric characteristics of the instruments used, as well as the methods for transferring standard values.
Measurements of diffuse reflectance factor may be used for the determination of optical properties such as the diffuse blue reflectance factor (blue brightness), color, light scattering and absorption coefficients of pulp, paper and board, as well as the opacity of paper.
This standard is applicable to the measurement of paper, board and pulps.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest edition of the normative document applies.
GB/T 450 Paper and board - Sampling for testing (GB/T 450-2002, eqv ISO 186:1994)
GB/T 740 Pulps - Sampling for testing (GB/T 740-2003, ISO 7213:1991, IDT)
GB/T 1543 Paper - Determination of opacity (paper backing) (GB/T 1543-1988, neq ISO 2471:1977)
GB/T 2679.1 Paper - Determination of transparent
GB/T 7974 Paper, board and pulp - Measurement of brightness - Diff/Geometry (GB/T 7974-2002, neq ISO 2470:1999)
GB/T 7975 Paper and board - Measurement of color (Diff/o-Geometry)
GB/T 10339 Testing method of light scattering and absorption coefficient for paper and pulps (GB/T 10339-1989, eqv ISO/DP 9416)
3 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
3.1
reflectance factor
the ratio, expressed as a percentage, of the radiant flux reflected by a body to that reflected by the perfect reflecting diffuser under the same conditions
3.2
diffuse reflectance factor, R
the ratio, expressed as a percentage, of the radiant flux reflected by a body to that reflected by the perfect reflecting diffuser under the same conditions of diffuse illumination described in this standard in an instrument calibrated in accordance with the provisions of this standard
3.3
intrinsic reflectance factor, R∞
the reflectance factor of a layer of test piece thick enough to be opaque
Contents of GB/T 7973-2003
Contents
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Basic conditions for transferring standard values
5 Instruments
6 Sampling
7 Preparation of test pieces
8 Procedure
9 Calculation and reporting of measurement results
Annex A (Normative) Instruments for the measurement of reflectance factor
Annex B (Informative) Calibration of instruments
