Portable Glossmeter Full Technical details and working Principle.

complete discussion of technicality behind the working principle and latest available technology for Gloss Checking with practical example along with available results at each parameter and stages.

1. YOGESH PANDEY,
AIMIL LIMTED, VADODARA
ELCOMETER, UK
Glossmeter

2. Glossmeter
 Gloss is a measure of light reflected by the surface of plastic film.
Significance
gloss measure the shiny appearance of films and surfaces.
It is used to compare two or more materials based on their appearance.
Gloss is associated with other visual aspects of surface appearance such as
reflected images, haze and texture.

3. Basic of light reflection
-3 « categories » of reflections :
Specular / Scattered / Diffuse
- Specular reflection: Mirrors, perfectly polished metals
Incoming and outgoing beams have the exact same angle
- « Scattered » reflection: Most materials fall into that category
Even if most of the light is reflected in the specular angle, surface defects will scatter the ligh creating a bell curve
deflection. The bell curve shape will depend on the microtopography of the surface
- Diffuse reflection: best example; White paper
Also called Lambertian reflection
Extreme case of scattered reflection where light is reflected in all directions with an isotropic distribution

4. Gloss
- First Glossmeter (Glarimeter): 1914
Well known and widely used
 Glossmeters measure the « shininess » / Brightness (quantity of the light directly reflected from
the surface)
 High gloss makes products visually appealing (Automotive, electronics, high end products)
 Mostly used angles: 20° (70+ GU) / 60° (10-70 GU) / 85°(<10 GU)
Limitations:
 Not sensitive to effects which reduce appearance quality
 Unable to mimic the human eye perception of the surface! The human eye evaluates much
more that the shininess of the surface…
Anything new since 1914? Yes!

5. What’s New?
-Gloss is definitively part of the answer. However, 2 products with
similar gloss can look very different… why?
- « Distribution effect » is the key
- In a glossmeter, the entering light is treated as one single value,
the distribution effect (variation) is not taken into account (like it
would be in the human eye). Beam is treated as a specular
reflection.
- Nowadays, equipment with light sensor arrays allow us to take
measurements that mimic the light reflection on the human eyes
cones.
Incorrect reading
Correct reading
Array of light sensors
Human eye

6. What’s New?
- What are the parameters this new technology allows us to quantify?
- Haze
- DOI (Distinctness Of Image)
-% Reflection (Reflected Image Quality)
even more acurate Gloss values!
High Gloss
High Orange Peel
High Gloss
Low Orange Peel

7. Haze
Haze is produced by imperfections/irregularities on the surface that affect
the light distribution around the specular angle.
Haze is sometimes called « gloss haze » as both are related. Haze is actually
the sum of the gloss around the specular angle (-3° to -1 ° and +1 ° to +3 °):
100% reflection within 1° of specular angle Haze = 0
Surfaces without haze show a deep reflection and high reflected contrast
Surfaces with haze can be seen as « milky »/ « blurry » (2)
Haze is sometimes compared to « turbidity »

8. DOI
DOI measures the Distinctness Of Image: How
clearly an image appears on a reflective
surface
A low DOI indicates image distorsion (perfect
mirror has a DOI of 100)
DOI quantifies the « sharpness » of the image
A low DOI can be seen as the result of a high
haze
Haze increases / DOI decreases

9. RIQ (% Reflection )
RIQ (Reflected Image Quality) is an improved
version of the DOI
RIQ provides a better response to orange peel
effects on a wider range of materials and
textures.
For low gloss surfaces or on samples with low
orange peel , RIQ provides results even more in
accordance with our visual perception
(compared to DOI)
Samples 5 to 10 above show similar DOI results but
RIQ measurements provide discriminant data

10. Case study:
4 « similar » samples
 
 
4 similar samples were evaluated against each other
Identifications: Plate 1 / Plate 2 / Plate 3 / Plate 4
Initial color measurements (similar)
Gloss measurements on 24 specimens of each samples
Plate 2 is less glossy: « Rejected »
Similar values: Non discriminant parameter
Plate 1Plate 2Plate 3 Plate 4

11. Case study
Haze measurements
on 24 specimens of each samples
Ideal value: 0
Best contrast
DOI measurements
on 24 specimens of each samples
Ideal value: 100
Best reflection

12. Case study
Samples
performance:
++ : Excellent performance / results
-- : Poor performance / results

13. Case study
Plate 3
Plate 4
Plate 1
Plate 2

14. Test method
STANDARDS:
AS/NZS 1580.602.2, ASTM C584, ASTM C523, ASTM D523, ASTM D1455, ASTM D2457,
ASTM D4039, ASTM D4449, ASTM D5767, ASTM E430, ASTM E2387, BS 3900 D5,
DIN 67530, ECCA T2, EN 12373-11, EN 13523-2, ISO 7668, ISO 2813, ISO 13803,
JIS K 5600-4-7, JIS Z 8741, TAPPI T 653 (20°)
Specimen and conditioning
Specimen surfaces must have good planarity and free warpage, waviness or curvature.
The test specimen is conditioned at 23± 2ºc and 50 ± 5% relative humidity for not less than
40hrs prior to test.

15. Equipment

16. Procedure
The instrument is turned on and placed on a black glass primary standard.
The control knob is adjusted so that the meter indicates the value
assigned to the primary standard.
The sensor is placed on the specimen surface and gloss value is read
directly from the analog or digital display.
The instrument is calibrated regular intervals to ensure that the instrument
reading is particularly constant
The instrument fails to repeat readings of the standard within 2% of the
prior setting, the intervening result should be rejected.

17. Factors affecting
Surface property : Specular gloss is primarily due to reflection at the
surface, therefore, anything that changes the surface physically or
chemically is likely to affect the gloss.
Surface of the material : It should be perfectly smooth. Smoothnes
depends on the quality of the surface of mold or die used to make the
part.
Incidence angle : As the incidence angle increases, gloss value for the
surface also increases.

18. elcometer technical specification
Please click on link below and refer elcometer technical specification for
glossmeter
http://www.elcometer.com/images/stories/PDFs/Datasheets/English/480.pd
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http://www.elcometer.com/images/stories/PDFs/Datasheets/English/408.pd
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19. For any assistance please dial or contact on below no. and email address
Yogesh pandey (Aimil Limited )
[email protected]

[phone], [phone]
www.linkedin.com/in/yogesh-pandey-355784147