ISO 3405 Petroleum products - Determination of distillation characteristics at atmospheric pressure
11 Expression of results
11.1 Report the sampling procedure used.

11.2 Report all volume percentages to the nearest 0.5 % (V/V) or 0.1 % (V/V), and all thermometer readings to the nearest 0.5 °C or 0.1 °C, appropriate to the apparatus being used. The 0.5 % (V/V) and 0.5 °C apply to the manual procedure, and the 0.1 % (V/V) and 0.1 °C apply to the automated procedure.

11.3 Report a reference to manual or automated procedure, whichever was used.

11.4 Unless specifically requested (see note 3 in 10.2), thermometer readings shall be corrected to 101.3 kPa barometric pressure before being reported. When such special arrangements have been made, report the observed values in accordance with the rounding rules described in 11.2, together with the laboratory barometric pressure. In these cases, also report the residue and loss as "observed".

11.5 For groups 0 and 1, or any other material with a loss exceeding 2.0 % (V/V), report the relationship between the thermometer reading and the percent volume evaporated. For groups 2, 3 and 4 generally, report the relationship between thermometer reading and the percent volume recovered. Clearly identify which relationship is being used.

11.6 Report samples in groups 0, 1 and 2 as "dried" if the default procedure described in 6.3.1 has been carried out.

11.7 Report the substitution of a low-range thermometer for the high-range thermometer, if the conditions of 9.7.2.1 have been applied.

12 Precision
12.1 General
The precision as determined by statistical examination according to ISO 4259 of interlaboratory test results on matrices of gasolines, kerosines and gas oils by both manual and automated procedures is given in 12.2 and 12.3, and factors and/or precision are indicated in Tables 6, 7 and 8. Statements of bias are given in 12.4.
12.1.1 To determine the precision of results other than the initial boiling point (IBP) and final boiling point (FBP), it is generally necessary to determine the rate of change of temperature at that particular point. This variable, ΔC/ΔV, is equal to the change in temperature per percent recovered or evaporated, and is calculated from the following equation:
ΔC/ΔV = (TU - TL)/(VU - VL)
where
TU is the upper temperature;
TL is the lower temperature;
VU is the percent volume recovered or evaporated corresponding to TU;
VL is the percent volume recovered or evaporated corresponding to TL.

Table 5 gives the data points to be used to determine the slope at specific percentages recovered or evaporated. For samples in group 1, the precision data reported are based on slope values calculated from percent evaporated data, and for samples in groups 2, 3 and 4, the precision data reported are based on slope values calculated from percent recovered data.

In the event that the final boiling point occurs prior to the 95 % (V/V) evaporated or recovered point, the slope at the final boiling point, if required, is calculated from the following equation:
ΔC/ΔV = (TFBP - TH)/(VFBP - VH)
where the subscripts are:
FBP is the final boiling point;
H is the highest volume reading, to the nearest 5 % (V/V), prior to the final boiling point.

12.2 Repeatability
12.2.1 Group 0. With proper care and strict attention to details, duplicate results obtained for the final boiling point should not differ from each other by more than 3.5 °C in more than one case in twenty. Differences in duplicate thermometer readings for each specified volume percentage evaporated should not exceed the amounts equivalent to 2 ml of distillate at each point in question (see annex C).

12.2.2 Group 1. The difference between two 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 the test method, exceed the values given in Table 6 in only one case in 20.

12.2.3 Groups 2, 3 and 4. The difference between two 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 the test method, exceed the values given in Table 7 (manual) or Table 8 (automated) in only one case in 20.

12.3 Reproducibility
12.3.1 Group 0. The reproducibility of the test method for this group has not been determined.

12.3.2 Group 1. The difference between two single and independent test 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 the test method, exceed the values given in Table 6 in only one case in 20.

12.3.3 Groups 2, 3 and 4. The difference between two single and independent test 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 the test method, exceed the values given in Table 7 (manual) or Table 8 (automated) in only one case in 20.

12.4 Bias
12.4.1 Absolute bias
Due to the use of total immersion mercury-in-glass thermometers or electronic temperature-measurement devices designed to emulate them, the distillation temperatures given in this International Standard are somewhat lower than the true temperatures. The amount of absolute bias depends on the product being distilled, the actual temperature, and the thermometer being used.

12.4.2 Relative bias
There exists a bias between the empirical results of distillation properties obtained by this International Standard and those obtained by other standards which may give results closer to true boiling point distribution. The amount of such bias has not been determined.

12.4.3 Internal bias
For groups 1, 2, 3 and 4, the bias between manual and automated apparatus is shown in annex D.

13 Test report
The test report shall contain at least the following information:
a) a reference to this International Standard;
b) the type and complete identification of the product tested;
c) the result of the test (see clause 11);
d) any deviation, by agreement or otherwise, from the procedure specified;
e) the date of the test.