A spectrophotometer is a device that measures light intensities at different wavelengths. It works by splitting light into a spectrum and detecting intensities with a charged couple device. Key components include an illuminant, optics to direct light, a monochromator to split light, and a photodetector. There are single and dual beam types, with dual beam minimizing errors by comparing sample and reference beams. Calibration ensures repeatability, and spectrophotometers are used to measure color and help with tasks like quality control and color matching.

1. Instruments for color measurement
Spectrophotometer

2. Prepared By : Mazadul Hasan sheshir
ID: 2010000400008
13th Batch (session 2009-2013)
Department : Wet Processing Technology
Email: mazadulhasan@yahoo.com
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Southeast University
Department Of Textile Engineering
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3. Spectrophotometer is a device
that measure the light intensities
as a function of wave length.
It does it by diffracting the light beam into a
spectrum of wavelength, detecting the light
intensities with charged couple device.

4. Spectrophotometer

5. Machine Name: Spectophotometer
Brand Name: GretagMacbeth
Model No: Color-Eye 7000A
Origin: U.S.A

7. Types
• Colorimeter
• Spectrophotometer
– Single beam
– Double beam

8. 01.Color measurement & calculation
02.Recipe formulation & cost calculation
03.Quality Control management & shade sorting
04.Match prediction & color correction
Functions of Spectrophotometer

9. Spectrophotometer

10. Working principle of a spectrophotometer

11. Single beam
• Old type
• Cheap
• Calibration tiles use as a
standard light.
• Spherical error can not
be minimized.
Dual beam
• New type.
• Relatively expensive.
• Two beams reference as
well as reflected
analyses and it is
compared with
reference light.
• Spherical error can be
minimized.
Single beam Vs Dual beam

12. Dual beam spectrophotometer
spectrophotometer

13. • A source of light (Illuminant)
• The way in which light is made to fall on the
object. (optics and viewing geometry)
• The method of dispersing the light into
spectrum colors (monochromation)
• The system of detecting the relative intensity
of the reflected beam (photodetection)
Anatomy of a spectrophotometer

14. Illuminant
1. Tungsten halide lamps.
2. Xenon arc lamp.
3. Pulsed xenon arc lamp (PXA)

15. • Normal optics
– Monochromate→ Reflect →Photodetect
• Reverse optics
– Reflect →Monochromate →Photodetect
Optics

16. The four CIE standard geometries are:
1. illumination at 45 degrees and light collection at the normal, 45/0;
2. normal illumination and light collection at 45 degrees, 0/45.
3. diffuse illumination and light collection at the normal, D/0;
4. normal illumination and diffuse light collection, 0/D
Viewing geometry

17. Viewing geometry

18. 8 8
GT
L
L = Lamp
S = Sample
GT = Gloss trap
d/8o geometry

19. • Prism
• Wedge Type
• Grating
Monocromation

20. • Silicone photodiodes (SPD)
• Photomultipliers tube (PMT)
Photodetect

21. 8º
8º
Reference Fibre
Optic to MC90
Sample
Fibre
Optic to
MC90
Fully Automatic
Zoom Lens
D65 Filter
Xenon Flash Lamp
UV Filter
Wheel
S
a
m
p
l
e
152 mm Diameter
Integrating Sphere
Specular Port
Spectrophotometer

22. Spectrophotometer

23. • Calibration ensures repeatability result of a
spectrophotometer. Before going for calibration we need to
look out following matters –
– Aperture size
• LAV (25 mm)
• MAV (10 mm)
• SAV (5 mm)
• USAV
– Spcular component
• Included
• Excluded
• Gloss
– UV Filter
• Included
• Excluded
Calibration of a spectrophotometer

24. • White tile
• Black trap
• These values in advance
stored in the software for
comparison in each time.
Component used for calibration

25. • In each time software calculates a correction factor A1 at
all wavelengths. If there is also a zero offset correction at
each wavelength A2 the software calculates the correct
reflection factor Rc from each measured reflection factor
Rm at all wavelengths.
– Rc = RmA1 + A2
• This means that the displayed reflection factors Rc are all
relative to a perfect diffuser with a 100% reflection at all
wavelengths.
How calibration is working

27. • Dust may change the whiteness of sphere so keep the room dust
free and time to time clean the sphere with a vacuum cleaner but
keep in mind it should effect the color of the sphere.
• Spectrophotometer should handle softly.
• Proper electric stabilization is required.
• During measure of sample, check it and it should be completely
immaculate from undesirable material.
• After procurement, it is necessary to verify its conformation to
BCRA tile standard and it should be verified time to time by a
professional.
Maintenance of a spectrophotometer

28. • Always measurement should be in such a way
so that it should not be influenced by any back
up material for this it may be fold four times.
• For getting accurate result, measurement
should be made four times for a sample by
rotating 90o at each time.
Sample measurement

29. • Purpose of such measurement.
• Number of sample to be measured per shift.
• Precision required.
• Availability of professional person.
• Distance between the dye house and instrument
service centre.
• The availability of spare parts and facility with the
supplier
How to select a spectrophotometer

30. Spectrophotometer works on the
basis of kubelka munk theory

31. Software
01.Datacolor Tools ( DCT-Tools )
02.Datacolor Match ( DCI –Match )

33. Parts of Spectrophotometer

34. •To collect recipe from Data Color.
•To measure CMC difference. (Pass/Fail decision).
•To give staining, wash fastness, light fastness result.
•To know the metameric value & dye concentration.
•To give topping recipe.
Purposes:

35. Specifications:
Feature Description
Instrument Type Dual-beam spectrophotometer
Measurement Geometry Diffuse illumination and 8° viewing
Illumination Source Pulsed xenon filtered to approximate D65
Sphere Diameter 152 mm / 6.0 in
Specular Port Automated included or excluded
Spectral Analyzer Proprietary SP2000 analyzer with dual 256
diode array and high resolution holographic
grating
Transmittance Measurements No
360 nm to 700 nm
Reporting Interval 5 nm or 10 nm(1)
Effective Bandwidth 5 nm or 10 nm
Photometric Range 0 to 200%
Black Trap High performance
20 Read Repeatability On The White Tile
Using Dual Flash (CIELAB)
0.01 (max)
Inter-instrument Agreement(2) for
Reflectance (CIELAB)
0.15 (max) , 0.08 (avg.)

36. Feature Description
Lens 4 position auto zoom
Aperture plates for reflection
measurements
3 standard (LAV, SAV, USAV)
2 optional (XUSAV)
LAV 30 mm illuminated
26 mm measured
MAV 20 mm illuminated
16 mm measured
SAV 9 mm illuminated
5 mm measured
USAV 6.6 mm illuminated
2.5 mm measured
XUSAV(3) 3.0 mm illuminated
2.5 mm measured
Reflection Aperture Plate Detection Yes
UV Calibration Yes
Automatic UV Control Automatic UV calibration for the measurement of
fluorescent Specimens with UV cutoff filters at 400
nm, 420 nm and 460 nm

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