Tappi Versus Iso Brightness Scale

Posted on 16-09-2021 by admin

Tappi Versus Iso Brightness Scale System
Tappi Versus Iso Brightness Scale Calibration
Tappi Versus Iso Brightness Scale 2016
Tappi Versus Iso Brightness Scale 10

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Paper brightness is a gauge of how well the lignin component of paer has been removed from the paper pulp. Xenosaga ds english patch. Papers with large amounts of residual lignin will have lower brightness. Paper mills use fillers such as, calcium carbonate, chalk, and titanium dioxide to increase the brightness of a paper.

Paper Brightness 'Brightness' refers to a specific measure of how much light a sheet of paper reflects. Uses the GE/Tappi scale and is a different brightness measurement system than the International scale. The comparison scale below, along with the new brightness icon, will guide you through the different numbers.

Measuring Paper Brightness

Paper brightness can be tested using 2 different methods. In the US, the TAPPI T 452 standard is used. The international community uses ISO standards, the ISO brightness tester. The TAPPI T 452 standard calls for a pad of paper to be illuminated at 45º and the resulting reflected light read at the 457 nm. – Which falls in the blue portion of the visible light spectrum.

TAPPI T 452 om-08 Brightness of pulp, paper and paperboard (directional reflectance at 457 nm) Staples launches unified paper brightness standard using TAPPI scale (10/04/04) This method is for the determination of the brightness of white, near-white, and naturally colored pulp, paper, and paperboard.
The brightness scale applicable to this method is the same as the brightness scale described in T 525. In contrast to TAPPI T 646 “Brightness of Clay and Other Mineral Pigments (45°/0°),” which uses 45° illumination and perpendicular viewing, this method utilizes an instrument with an integrating sphere to provide hemispherical (diffuse.

The test is sensitive to the grain direction of the paper, so measurements must paper direction must remain consistent during the test. The brightness scale is based on the 100% reflectance of a standard magnesium oxide tile.

Standard Spectroreflectometer
Specification

ISO-standardization

AUTOELREPHO® conforms to ISO standards

Determination of color

Stuck to dogs knot. The determination of color is accomplished according to the CIE Colorimetry Publication No. 15.2. (1986) Vienna

Optical design

Measuring geometry d/0°
Diameter of the integrating sphere 150 mm
Viewing aperture Ø 34 mm
Effective measurement area Ø 30 mm
Dual-beam optimized optical design
Ø 32 mm achromatic lens system

Specular factor

Excluded or included

Light sources

AUTOELREPHO® Combined Multisource
Continuous lighting
Simulated CIE illuminants C and D65 etc.
Indoor lighting with adjustable UV-content (optional)
Triplet-free illumination
Sphere error eliminated, thus reliable detection of:
- Total reflectance factor with UV
- Reflectance factor without UV
  (= Base chromaticity ; Grundweisse)
- Fluorescence component WF
- Whiteness W and tint TW

Calibration

16 different calibration scales
White and black calibration with neutral standards
Multicalibration, neutral and/or color standards in same photometric scale
Spectral calibration, up to 15 calibration standards in same photometric scale
Fluorescence calibration with direct entry of numerical calibration values
Automatic calibration capability

UV - control

Measurement and adjustment of the UV content in the integrating sphere by automatic adjustable, numerical constant UV-generator

UV - cut-off

UV totally eliminated, or one of: 380 nm, 400 nm, 420 nm, 435 nm,
455 nm, 460 nm

Colorimetric functions

Observation angles: 2° and 10°
ISO - brightness (R457 nm)
Calculated TAPPI-brightness (R457 nm)
D65 - brightness (R457 nm), (UV-off, R457 nm)
Reflectance factors Rx, Ry, Rz
CIE Tristimulus values X, Y, Z. Ratios X / X0, Y / Y0, Z / Z0
CIE Dominant wavelength λD (380-780 nm incl. purple area)
CIE Excitation purity Pe%
CIE 1931 and 1964 chromaticity coordinates x,y
Y-value (luminance)
CIE L*a*b* color coordinates
CIE L*a*b* color differences ΔL*, Δa*, Δb*, ΔE*
CIE Whiteness W. CIE Tint TW
CIE Whiteness W10. CIE Tint TW10
Δ CIE - Whiteness (WhitenessD65 – WhitenessUV-off)
Δ Fluorescence - R457 (R457D65 - R457UV-off)
Residual fluorescence
Yellowness
ISO - opacity
Transparency
Light scattering coefficient, s
Light absorption coefficient, k
K & N - test
Density
Metamerism index
CMC Color difference

MEASUREMENT MODES

1. ISO Brightness measurement mode

Filter function R457 nm, 44 nm HBW

2. CIE tristimulus X,Y,Z measurement mode

3. Fluorescence mode (option)

Total reflectance factor with UV (C, D65 etc.)
Reflectance factor without UV (C, D65 etc.)
Fluorescence component WF

4. Spectral measurement mode (option)

Spectral data 380 nm – 700 nm
Optional 360 nm – 700 nm
Numerical and graphic spectral reflectance data

5. Residual ink 950 nm mode (option)

(Determination of effective residual ink concentration = ERIC
by infrared reflectance measurement)

6. Light fastness test (option)

Adjustable timing 5 min – 24 hrs
Adjustable UV content in the integrating sphere

Measurement range

Photometric range 0.000 to 500.000 % R
Dynamic range from +2 500 000 units to -2 500 000 units

Reproducibility

Short time reproducibility 0.001 % R
Long term stability 0.01 % R/24 h

Accuracy of reading

Reflectance factors 0.001 % R
Dominant wavelength 0.01 nm
Excitation purity 0.01 Pe%
Chromaticity coordinates x,y < 0.0001
CIE L*a*b* color coordinates 0.001

Measurement time

Adjustable measurement time, from 10 ms to 2.5 s / reflectance factor.

Measurement principle

Optical integrating system
Continuous lighting with AUTOELREPHO® Combined Multisource
Latest filter technology
Enables determination of up to 100·109 different colors, meaning ultra high precision in detection of very small color differences and in low level detection, for example measurement of dominant wavelength of perfect diffuser; reflectance values near 100 % R or of black velvet; reflectance values near zero.

OPTIONS