ASTM D1218 : 99

Standard Test Method for Refractive Index and Refractive Dispersion of Hydrocarbon Liquids

Standard Details

1.1 This test method covers the measurement of refractive indexes, accurate to six units in the fifth decimal place, and refractive dispersions, accurate to twelve units in the fifth decimal place, of transparent and light-colored hydrocarbon liquids that have refractive indexes in the range from 1.33 to

1.50, and at temperatures from 20 to 30°C. The test method is not applicable within the accuracy stated to liquids having colors darker than No. 4 ASTM Color as determined by Test Method D 1500, to liquids having bubble points so near the test temperature that a reading cannot be obtained before substantial weathering takes place, to liquids having a refractive index above 1.50, or to measurements made at temperatures above 30°C.

Note 1-The instrument can be successfully used for refractive indexes above 1.50, and at temperatures both below 20°C and above 30°C, but as yet certified liquid StandardDetails for the ranges above a refractive index of 1.50 are not available, so the precision and accuracy of the instrument under these conditions have not been evaluated. Similarly, certified refractive indexes of liquids at temperatures other than the 20 to 30°C range are not available, although the instrument can be used up to 50°C.

1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.