Active Standard ASTM D5771 | Developed by Subcommittee: D02.07
Book of Standards Volume: 05.02
Historical (view previous versions of standard)
Significance and Use
For petroleum products and biodiesel fuels, the cloud point is an index of the lowest temperature of their utility for certain applications. Wax crystals of sufficient quantity can plug filters used in some fuel systems.
Petroleum blending operations require precise measurement of the cloud point.
This test method can determine the temperature of the test specimen at which wax crystals have formed sufficiently to be observed as a cloud with a resolution of 0.1°C.
This test method provides results that, when rounded to the next lower integer, are equivalent to Test Method D2500. Refer to 12.2.
This test method is more precise than Test Method D2500.
Note 1—According to interlaboratory examination, the reproducibility of this test method has been found to be more precise than Test Method D2500.
1.1 This test method covers the description of the determination of the cloud point of petroleum products and biodiesel fuels that are transparent in layers 40 mm in thickness, by an automatic instrument using an optical device.
1.2 This test method covers the range of temperatures from −60 to +49°C with temperature resolution of 0.1°C, however, the range of temperatures included in the 1997 interlaboratory cooperative test program only covered the temperature range of –56 to +34°C.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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 (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D2500 Test Method for Cloud Point of Petroleum Products
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D6708 Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purport to Measure the Same Property of a Material
Energy Institute StandardIP219 Test Method for Cloud Point of Petroleum Products
Other StandardIEC751 Industrial Platinum Resistance Thermometer Sensors
ICS Number Code 75.160.20 (Liquid fuels)
UNSPSC Code 15101500(Petroleum and distillates)