ASTM D5706 Standard Test Method for Determining Extreme Pressure Properties of Lubricating Greases Using a High-Frequency, Linear-Oscillation (SRV) Test Machine
10. Report
10.1 Report the following information:
10.1.1 Report all parameters used to evaluate material as follows:
10.1.1.1 Temperature, °C,
10.1.1.2 Stroke, mm,
10.1.1.3 Frequency, Hz,
10.1.1.4 Test ball,
10.1.1.5 Test disk,
10.1.1.6 Lubricating grease test specimen, and
10.1.1.7 Type of procedure - Procedure A or Procedure B.
10.2 Report the highest test load (pass load) at which no seizure occurred and when required by specification, include a copy of the friction recording (sample recording chart), which is in general recommended. In SRV models III, IV, and V, friction and stroke can be recorded and displayed simultaneously.
11. Precision and Bias
11.1 Eighteen cooperators tested eight greases at two temperatures having average load carrying capacities in the SRV apparatus ranging from approximately 200 N to approximately 700 N. The statistical analysis of data from this interlaboratory test program can be obtained from ASTM Headquarters by requesting Research Report RR:D02-1410 7 or read in Dickey's publication. The stroke was 1.0 mm for Procedure A.
11.2 The following criteria should be used for judging the acceptability of results (95 % probability) for lubricating greases which have load carrying capacities of 1200 N or less in the SRV apparatus using Procedure A with 1.0 mm of stroke.
11.2.1 Repeatability - The difference between successive results obtained by the same operator with the same apparatus under constant operating conditions on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the following values only in one case in twenty.
For tests run at 50 °C: 0.7X
For tests run at 80 °C: 0.6 (X + 122)
where:
X = the average of two results, N.
11.2.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical test materials would, in the long run, exceed the following values only in one case twenty.
For tests run at 50 °C: 1.3X
For tests run at 80 °C: 1.2 (X + 122)
where:
X = the average of two results, N.
11.3 Bias - The evaluation of load-carrying capacity of lubricating grease by this test method has no bias because load-carrying capacity can be defined only in terms of the test method.
11.4 Using this ASTM test method, the DIN 51834 working group conducted international round robin tests with a stroke increase to 1.5 mm in 2001 (with 32 cooperators), 2002 (with 26 cooperators), and 2003 (with 23 cooperators) at 80 °C with two greases using Procedure B, 1.5 mm of stroke, a grease apply caliper, and 15 min of running-in. The results are given in Table 1.
11.5 Using the Procedure B (1.5 mm of stroke) of this ASTM test method, the DIN 51834 working group conducted international round robin tests in 2011 (with 41 cooperators) testing six greases. The precision values from the 2011 round robin test displayed a better precision as those stated in Section 11.
12. Keywords
12.1 extreme pressure; lubricating grease; oscillating; SRV
