Research Report RR:D02-1740
At the June 2010 meeting of D02.07.D a limited interlaboratory study was approved to establish confidence in revisions to the apparatus utilized in test methods D5771 and D5950. A newer model of apparatus has been in use for several years which utilizes an internal cooling source, the methods currently reference cooling being supplied from an external source. While there are no other differences in the apparatus and test conditions, the committee agreed that a small study using at least five instruments and five samples in duplicate spanning the temperature range of the precision would be sufficient to establish the confidence with the internal cooling source version. The design of the study eventually resulted in nine total samples and six laboratories each for the external cooling (CPP97) and the internal cooling (CPP 5Gs) apparatus using D5950, Standard Test Method for Pour Point of Petroleum Products (Automatic Tilt Method) and five total samples and six laboratories each for the external cooling (CPP97) and the internal cooling (CPP 5Gs) apparatus using D5771 Standard Test Method for Cloud Point of Petroleum Products (Optical Detection Stepped Cooling Method). The samples were a variety of fuels and lubricants covering the range of temperatures from � 60 to +10�C, with the precision range of 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 blind duplicates and coded such that the duplicate sample was unknown, and no two labs had the same sample coding. When the samples were tested by D5950, two complete sets with different codes were shipped to allow testing by the typical 3�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