A computer program has been developed that converts between the notations of the Munsell, OSA‐UCS, NCS, DIN, and Coloroid colour order systems and the CIE, CIELAB, and CIELUV colour specification systems. The intention of this article is to outline the development of this program and its structure. Particular attention is given to the accuracy of the program and its associated databases.

An earlier article described the use of a colour notation conversion program to measure the accuracy of the NCS, DIN and OSA-UCS color atlases. This article describes the application of the same program to compare the perceptual scaling of the Munsell, NCS, DIN, and Coloroid systems with that of the OSA-UCS system. Five OSA-UCS cleavage planes were selected which represent a varied but systematic sampling of OSA-UCS colour space. The samples contained on these planes were converted onto the colour spaces of the Munsell, NCS, DIN and Coloroid systems. The converted points have been displayed graphically for ease of comparison.

Details of an expanded and improved computer program for the interconversion of colour notations are presented. This article describes the inclusion of the Colorcurve, SCA 2541, and HunterLab systems, expansion of the DIN and RAL implements, extension of the NCS aim point database, improvements to the OSA‐UCS and Coloroid conversion algorithms, a direct spectral curve input facility, and the inclusion of CIELAB, CIELUV, HunterLab, CMC[1:1], FMC‐1, and FMC‐2 colourdifference formulas. © 1992 John Wiley & Sons, Inc.

In this investigation dielectric constant and loss tangent values of coal samples were computed from measurements made at microwave frequencies (8.2–12.4 GHz). Two different waveguide methods were used in the measurements. One technique utilized a finite sample and two reactive terminations, and the other required the use of an infinite sample simulated in the laboratory by a very long specimen. For each of the two Pittsburgh seam coal samples, dielectric constant and loss tangent variations were also measured as a function of moisture. Typical moisture contents of 10% and 15% were examined. Electromagnetic propagation through a single layer of coal seam was then investigated analytically as a function of coal depth.

In 1985 a research program was instigated to determine the feasibility and desirability of developing a computer based colour notation conversion program. Results indicated that the development of such a program covering the Munsel, NCS, DIN, OSA‐UCS, Coloroid, CIELAB and CIELUV colour specification systems for use as a research tool was both feasible and desirable. The program was completed early in 1989 and this is the first of a number of articles that uses this program as a research tool. The colour notation conversion program has been used to evaluate the accuracy of the samples which comprise the NCS, DIN and OSA‐UCS colour atlases.