Dispersed Organic Matter Vitrinite Reflectance Accreditation Program (DOMVR)
Six (6) samples prepared as sedimented grain mounts, cut perpendicular to the sedimentaton plain and re-embeded have to be analysed for entering the program.
As there is no specific ISO standard for the measurement of vitrinite reflectance of dispersed organic matter the ISO standard for vitrinite reflectance measurements in coal (ISO 7404-5; 2009) is used as reference and additional instructions are provided:
- The parameter to be evaluated is mean vitrinite random reflectance percentage, regardless the maceral sub-group. No huminite/vitrinite distinction applies as a function of coalification. The measurements to be made are of vitrinite reflectance using a light train without a polar and without stage rotation.
- The values reported should be the result of averaging at least 50 readings. No less than 30 values should be measured in the samples with scarce suitable particles.
- The analysis should be made following traverses perpendicular to the bedding. If the requested number of readings (50) is reached before completing a traverse additional fields should be measured and reported.
At the conclusion of the exercise, the results from all participating petrographers are pooled. A statistical evaluation identifies those petrographers whose results do not fall within acceptable limits of departure from the group mean or that report results which are consistently higher or lower than the group mean (see Statistical Evaluation in Detail).
Petrographers who are not accredited in dispersed organic matter vitrinite reflectance have to perform six (6) complete analyses. These six sets of analyses will then form the petrographer's new data file that will be statistically assessed and to which all subsequent analyses are added and evaluated.
INTERNATIONAL COMMITTEE FOR COAL AND ORGANIC PETROLOGY (ICCP) (1998). The new vitrinite classification (ICCP System 1994). Fuel, 77:349-58.
Sýkorová, I., Pickel, W., Christianis, K., Wolf, M., Taylor, G.H., Flores, D., 2005. Classification of huminite—ICCP System 1994. International Journal of Coal Geology 62, 85–106.
ISO 7404-5, 2009. Methods for the Petrographic Analysis of Coal—Part 5: Methods of Determining Microscopically the Reflectance of Vitrinite. International Organization for Standardization, Geneva, Switzerland. 14 pp.