ASTM D5306 Standard Test Method for Linear Flame Propagation Rate of Lubricating Oils and Hydraulic Fluids
9. Calculation and Report
9.1 Calculate the linear flame propagation rate as follows:
linear flame propagation rate = dv/p
where:
d = distance between thermocouples, mm (see Fig. 1),
v = chart speed in mm/s, and
p = distance measured peak to peak between thermal effects, mm (see Fig. 2).
10. Precision and Bias
10.1 Precision:
10.1.1 Eight laboratories participated in a collaborative study to determine the precision and bias of this test method. The study was conducted by sending seven different fluids to participating laboratories. Since two different test procedures were used in Laboratory Number 4, some data were reported for Lab 4 and Lab 4A. For analysis purposes, Lab 4 and 4A were treated as independent, resulting in a total of nine laboratories.
10.1.2 The seven fluids used in the study are: Silicate Ester I, Phosphate Ester, MIL-H-5606, MIL-H-83282 I, MIL-H-5606 II, MIL H-83282 II, and Silicate Ester II. Each fluid was used in conjunction with two support materials, 3/4 and 4/5. Each combination of fluid and support was replicated five times.
10.1.3 Appendix X1 contains a table of summary data. The average flame propagation rate in millimetres per second is reported for each fluid and support combination for each laboratory. This was calculated from five replicates, except as noted. An overall average and a standard deviation, S, for each combination of fluid and support materials is reported as well. Note that all values in Table X1.1 are reported to three significant figures since the majority of raw data points were reported that way. Laboratories 4, 4A, and 8 reported two significant figures while Laboratory 7 reported four significant figures.
10.1.4 Annex A1 contains a table of precision statistics. The repeatability standard deviation, Sr, refers to an intralab variation. The reproducibility standard deviation, SR, refers to lab-to-lab variation. The 95 % repeatability and reproducibility limits are r and R, respectively.
10.1.5 The precision of this test method as obtained by statistical examination of interlaboratory test results is as shown in 10.1.5.1 and 10.1.5.2.
10.1.5.1 The difference between successive test 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 this test method exceed the repeatability limits (r) listed in the tables of precision statistics (see Annex A1) only in one case in twenty.
10.1.5.2 The difference between independent results obtained by different operators working in different laboratories on identical test material, would in the long run, in the normal and correct operation of this test method exceed the reproducibility limits (R) listed in the table of precision statistics (see Annex A1) only in one case in twenty.
10.2 Bias - The linear flame propagation rate is defined by the present test procedure. No independent measurement is available upon which to base a statement of test bias. No bias statement is possible for this reason.
11. Keywords
11.1 fire resistance; flame propagation; flammability; hydraulic fluids
