Avantes

For online and offline reflective color measurements, AvaSoft-COL is the ideal companion. This application provides a precise way to perform color measurements using the basic principles and techniques defined by the International Commission on Illumination (CIE). The CIE 1976 L*a*b* color parameters are calculated, along with other parameters, like Hue, Chroma and X, Y, Z.

These parameters can be displayed in a CIELAB chart or in a graph versus time. Another possibility is saving the measured L*a*b* values to an online database and using one of the products from the database as a reference color. Color differences (ΔE_Lab, ΔL*, Δa*, or Δb*) are done by comparing the measured L*a*b* values to the stored database values.

The color of an object can be expressed by the CIE 1976 (L*a*b*) color space. L* describes the brightness of the color. A positive value of a* describes the redness of the color, a negative a* the greenness. Similarly, yellowness is a positive b*, where blue is a negative b*. The L*a*b* values are derived from the CIE tristimulus values X, Y and Z of the sample (object) and the standard illuminant tristimulus values X_n, Y_n and Z_n.

The standard illuminant tristimulus values for X_n, Y_n, and Z_n are constant and depend only on the type of standard illuminant that has been chosen.

The CIE tristimulus values X, Y and Z of the color of an object are obtained by multiplying the relative power P of a standard illuminant, the reflectance R (or the transmittance) of the object, and the 1931 or 1964 CIE standard observer functions x_n, y_n and z_n (2 and 10 degree angles). The integral of these products over all the wavelengths in the visible spectrum (380 to 780 nm with a 5 nm interval) gives the tristimulus values.

Color chart
The color chart display features:

• Display in CIELAB chart, the actual sample color as well as the reference color with the corresponding ΔELab, ΔL*, Δa*, or Δb* values are displayed and saved as well.
• The settings for the LAB chart display can be changed, such as no graphical display of reference and sample color in order to speed up the measurements.
• The standard observer angle is selectable for 2° or 10°.
• The reference color can be saved to and loaded from a color database. The database contains, apart from all color parameters, a product ID and a display of the actual color. The database can be sorted alphabetically or in either value column.

Time series
The time series display has following features:

• Display in time series can be selected for any number of channels.
• For each channel a color parameter (L*, a*, b*, hue, C, X, Y, Z, ΔE_Lab, ΔL*, Δa*, or Δb*) can be selected. For each channel a different reference color can be selected, enabling color sorting.
• For each channel the time axis can be set to a different scale, allowing simultaneous display of long time and short term monitoring of the same parameter.
• For each channel the actual measured color, as well as the reference color (if in ΔE_Lab, ΔL*, Δa*, or Δb* mode) is displayed.
• The saved time series data can be displayed with extensive zooming and dragging options.