ASTM D6892 Test Method for Pour Point of Petroleum Products (Robotic Tilt Method)
1. Scope
1.1 This test method covers the determination of the pour point of petroleum products by an automatic instrument that tilts the test jar to detect movement of the surface of the test specimen with an optical device, after being removed from a regulated, stepped-bath cooling jacket.
1.2 This test method is designed to cover the range of temperatures from -57 to +51°C; however, the range of temperatures included in the 1998 interlaboratory test program only covered the temperature range from -51 to -11°C.
1.3 Test results from this test method can be determined at either 1 or 3°C testing intervals.
1.4 This test method is not intended for use with crude oils.
NOTE 1 - The applicability of this test method on residual fuel samples has not been verified. For further information on the applicability, refer to 13.4.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This standard does not purport to address all of the safety concerns, 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.
2. Referenced Documents
2.1 ASTM Standards:
D97 Test Method for Pour Point of Petroleum Products
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
2.2 Energy Institute Standard:
IP 15 Test Method for Pour Point of Petroleum Products
3. Terminology
3.1 Definitions:
3.1.1 pour point, n - in petroleum products, the lowest temperature at which movement of the test specimen is observed under prescribed conditions of test.
3.2 Definitions ofTerms Specific to This Standard:
3.2.1 no-flow point, n - in petroleum products, the temperature of the test specimen at which a wax crystal structure or viscosity increase, or both, impedes movement of the surface of the test specimen under the conditions of the test.
3.2.1.1 Discussion - The no-flow point occurs when, upon cooling, the formation of wax crystal structures or viscosity increase, or both, has progressed to the point where the applied observation device no longer detects movement under the conditions of the test. The preceding observation temperature at which flow of the test specimen is last observed is the pour point.
3.2.2 tilting, vt - technique of movement where the test jar in a vertical position is moved towards a horizontal position to induce specimen movement.
3.2.2.1 Discussion - When the test jar is tilted and held in a horizontal position for 5 s without detection of movement of the surface of the specimen, this is the no-flow point and the test is complete.
