Micro carbon residue

Micro carbon residue, commonly known as "MCR" is a laboratory test used to determine the amount of carbonaceous residue formed after evaporation and pyrolysis of petroleum materials under certain conditions. The test is used to provide some indication of a material's coke-forming tendencies. The test results are equivalent to the test results obtained from the Conradson Carbon Residue test.
Test method.
A quantity of sample is weighed, placed in a glass vial, and heated to 500 °C. Heating is performed in a controlled manner, for a specific period of time, and under an inert (nitrogen) atmosphere . The sample experiences coking reactions, with volatiles formed being swept away by the nitrogen. The carbonaceous residue remaining is reported as a mass percent of the original sample, and noted as “carbon residue (micro).” 
Applications.
Micro carbon residue offers the same range of applicability as the test to which it is equivalent, Conradson Carbon Residue. Advantages of MCR include better control of test conditions, smaller samples, and less operator attention. Applications include: