Research Report RR:D02-1740
At the June 2010 meeting of D02.07.D a limited interlaboratory study wasapproved to establish confidence in revisions to the apparatus utilized in TestMethods D5771 and D5950. A newer model of apparatus has been in use forseveral years which utilizes an internal cooling source, the methods currentlyreference cooling being supplied from an external source. While there are noother differences in the apparatus and test conditions, the committee agreed thata small study using at least five instruments and five samples in duplicatespanning the temperature range of the precision would be sufficient to establishthe confidence with the internal cooling source version. The design of the studyeventually resulted in nine total samples and six laboratories each for theexternal cooling (CPP97) and the internal cooling (CPP 5Gs) apparatus usingD5950, Standard Test Method for Pour Point of Petroleum Products (AutomaticTilt Method) and five total samples and six laboratories each for the externalcooling (CPP97) and the internal cooling (CPP 5Gs) apparatus using D5771Standard Test Method for Cloud Point of Petroleum Products (Optical DetectionStepped Cooling Method). The samples were a variety of fuels and lubricantscovering the range of temperatures from – 60 to +10°C, with the precision rangeof the test methods being from -56 to +34°C. The higher temperature samples,above +34°C, were unable to be located. The samples were shipped as blindduplicates and coded such that the duplicate sample was unknown, and no twolabs had the same sample coding. When the samples were tested by D5950, twocomplete sets with different codes were shipped to allow testing by the typical3°C interval and also at the 1°C Interval.
D5950-14 Standard Test Method for Pour Point of Petroleum Products (Automatic Tilt Method)
D5771-17 Standard Test Method for Cloud Point of Petroleum Products and Liquid Fuels (Optical Detection Stepped Cooling Method)
Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants
Subcommittee D02.07 on Flow Properties