PURPOSE: To easily and highly accurately measure the 10% carbon residue of A oil in a short time by using a standard color liquid array which contains a bromthymol blue solution and instrument ink and the color of which is visually equivalent to the hue corresponding to the 10% carbon residue.
CONSTITUTION: The title color liquid array is obtained by mixing a bromthymol blue solution and instrument ink at an appropriate rate and diluting the mixture with an aqueous solution of acetic acid. At the time of preparing the color liquid array, the hue of the array is adjusted to that similar to the actual hues of objects to be measured, namely, the 10% carbon residues of various kinds of A oil by precisely subdividing the hue of the liquid array by dilution. Then prepared numerous standard color liquid containers 1b are filled with the standard color liquids by prescribed amounts and the sample of A oil diluted with kerosene is collected in a sample container 1a. The colors of the light rays from a light source 3 passed through the containers 1a and 1b through a light incident port 4, opal glass 5, and daylight filter 6 are subjected to colorimetry. The colorimetry is repeated until it is discriminated that the colors are the same by exchanging the container 1b one by one. Therefore, the 10% carbon residue of A oil can be measured with high accuracy in a short time.
MIYAMOTO AKIRA
NAJIMA TAKAYUKI
