ASTM D4530 test method for determination of carbon residue (Micro method)
4. Summary of Test Method
4.1 A weighed quantity of sample is placed in a glass vial and heated to 500°C under an inert (nitrogen) atmosphere in a controlled manner for a specific time. The sample undergoes coking reactions, and volatiles formed are swept away by the nitrogen. The carbonaceous-type residue remaining is reported as a percent of the original sample as "carbon residue (micro)".
4.1.1 When the test result is expected to be below 0.10 % (m/m), the sample can be distilled to produce a 10 % (V/V) bottoms, prior to performing the test.
5. Significance and Use
5.1 The carbon residue value of the various petroleum materials serves as an approximation of the tendency of the material to form carbonaceous type deposits under degradation conditions similar to those used in the test method, and can be useful as a guide in manufacture of certain stocks. However, care needs to be exercised in interpreting the results.
5.2 This test method offers advantages of better control of test conditions, smaller samples, and less operator attention compared to Test Method D189, to which it is equivalent.
5.3 Up to twelve samples may be run simultaneously, including a control sample when the vial holder shown in Fig. 1 is used exclusively for sample analysis.
