Historical (view previous versions of standard)
This method is for the determination of heptane-insolubles in petroleum oils and is applicable to samples that are fluid at about 80°C. This method covers the range of 0.01 to about 20 mass-% heptane-insolubles. Solid particulate materials interfere. The method may also be used to determine toluene-insolubles (see Note 1). More viscous or solid materials such as asphalts may be handled by the modification described in the APPENDIX. The data provided by this method may be used as an index to coking tendency of petroleum oils when considering their suitability as charge stocks to cracking or other processes.