BYK-mac i 12mm
- Measuring area: 12 mm diameter
- Menu guided operation according to your own sampling procedure
- Pass/Fail results displayed on the instrument for instant feed back at the line
- Professional data documentation and analysis with smart-chart software
Reliable readings at any time
In order to guarantee stable positioning, the BYK-mac i is equipped with trigger pins on the bottom plate of the instrument. If the pins do not have contact with the surface, an error message will be displayed. This ensures reproducible results on test panels as well as curved parts (r > 500 mm). Additionally, the surface temperature is measured and saved with each measurement.
Metallic Coatings
Today effect finishes play a dominant role in many applications as they make an object distinctively appealing. In contrast to conventional solid colors, effect finishes change their appearance with viewing angle and lighting conditions. Interference finishes show not only a lightness change with different viewing angle, but also a change in chroma and hue. The latest developments are special effect pigments, which create sparkling effects when lighting conditions change from sunlight to cloudy sky.
Instrumental Color Measurement of Effect Coatings
Multi-angle color measurement
ASTM, DIN and ISO standards define multi-angle color measurement to objectively describe the color of metallic finishes. Research studies show that a minimum of three, and optimally five viewing angles are needed. The measurement geometry for multi-angle color measurement is specified by aspecular angles. The aspecular angle is the viewing angle measured from the specular direction in the illuminator plane. The angle is positive when measured from the specular direction towards the normal direction.
For color QC, the colorimetric data L*, a*, b* (or L*, C*, h°) and delta E* can be used. The tolerances are usually higher for the near specular (15°, 25°) and the flop angle (75°, 110°) than the 45° tolerance. In order to have a unique tolerance parameter independent of color, weighted factors have to be used. Therefore, automotive companies often have set specifications on Δ E’ based on DIN 6175 using 3 or 5 angle instrumentation.
Another useful index is the flop index, a measure of the change in lightness of a metallic color as it is tilted through the entire range of viewing angles.
Flake Characterization
In addition to color changes our total perception is also influenced by the effect of the metallic flakes or other sparkling pigments. This effect changes with the lighting conditions, for example direct sunlight versus cloudy sky.
Sparkle
A sparkling or glitter impression can be observed under direct sunlight. This effect is often described with different words such as sparkle, micro brilliance or glint and is generated by the reflectivity of the individual effect pigment.
Therefore, it is influenced by the
- flake type and size
- concentration level of the effect pigment
- orientation of the effect pigment
- application method
The sparkle impression changes depending on the illumination angle.
Graininess
Apart from the sparkle effect under direct sunlight, another effect can be observed under cloudy conditions, which is described as coarseness or salt and pepper appearance.
This visual graininess can be influenced by the flake diameter or the orientation of the flakes resulting in a non-uniform and irregular pattern. The observation angle is of low relevance when evaluating graininess.
The BYK-mac i measures color at 6 angles with 45° illumination. The sparkle effect in direct sunlight is created under different lighting angles with very bright white LEDs.
The diffuse illumination for assessing the graininess is obtained by illuminating a sphere coated with BaSO4. The measured values are recorded using a high-resolution camera that is located perpendicular to the sample surface.
Visual Evaluation of Effect Coatings
As metallic finishes show a lightness change with different viewing angles, the sample needs to be tilted to create the same effect during visual evaluation. This effect is also referred to as “lightdark flop”. The bigger the lightness changes between the angles of view are, the more the contours of an object will be accentuated. In order to observe color travel of interference finishes, the panel should be moved to allow increasing or decreasing the angle to the light source.
IIn the last years a new generation of special effect pigments has become more and more popular. For some of these new pigments the color travels over a wide range. In order to fully capture the color travel of these interference pigments it is necessary to add viewing and illumination angles. To keep the whole procedure practical for industrial use with a portable spectrophotometer it was determined that an additional angle behind the gloss e.g. -15° is of benefit. Directional illumination is used versus circumferential illumination because circumferential illumination minimizes the contribution from directional effects such as the Venetian blind effect and surface irregularities.Thus, averaging of the circumferential illumination would cause the measured color values of two specimens to be the same, while visually the two specimens would not match.
Comes complete with:
- Multi-angle spectrophotometer
- Black calibration standard (7044)
- White calibration standard with certificate
- Color checking tile
- Effect checking tile
- Docking station with USB cable for data transfer (6360)
- Instrument interface cable for online data transfer (6413)
- Protective cap (6336)
- 2 light protection covers (6414)
- Seal replacement kit (6348)
- Cleaning set (6364)
- 2 rechargeable Li-ion battery packs (6359)
- Battery holder
- 4x AA batteries
- Software with 2 licenses for download:
- smart-lab Color (4862) or smart- process (4831)
- Manual
- Carrying case
- 1-day training
