ISO 3405 Petroleum products - Determination of distillation characteristics at atmospheric pressure
9.1 Apply heat to the distillation flask (5.2) and contents with the drip tip of the condenser (see 5.3) away from the wall of the graduated cylinder (5.7.1). Regulate the heating (5.5) at this stage so that the time interval between the first application of heat and the initial boiling point is as specified in Table 3.
9.2 Observe and record the initial boiling point to the nearest 0.5 °C or 0.1 °C as appropriate to the apparatus being used. If a receiver deflector is not being used, immediately move the graduated cylinder so that the tip of the condenser touches the inner wall.
9.3 Regulate the heating so that the time from initial boiling point to 5 % (V/V) or 10 % (V/V) recovered is as indicated in Table 3.
9.4 Continue to regulate the heating so that the uniform average rate of condensation from 5 % (V/V) recovered to 5 ml residue in the flask is 4 ml/min to 5 ml/min.
NOTE 1 Due to the configuration of the distillation flask and the conditions of the test, the vapour and liquid around the temperature sensor (see 5.8) are not in thermodynamic equilibrium. The distillation rate will consequently have an effect on measured vapour temperature, and thus this should be kept as constant as possible throughout the test.
NOTE 2 When testing group 0, group 1 or group 2 materials, the condensate may form non-miscible phases and bead upon the thermometer and in the neck of the distillation flask at a vapour temperature of approximately 160 °C. This is accompanied by a sharp (approximately 3 °C) dip in vapour temperature and a drop in recovery rate. The phenomenon may last for 10 s to 20 s, before the temperature recovers and the condensate starts flowing again. This point may be referred to as the "hesitation point".
9.5 Repeat any distillation that does not meet the conditions described in 9.1 to 9.4.
9.6 If a decomposition point is observed, discontinue the heating and proceed as directed in 9.10.
9.7 In the interval between the initial boiling point and the end of the distillation, observe and record data necessary for the calculation and reporting of the results of the test as required by the specification involved, or as previously established for the material under test.
NOTE These observed data can include thermometer readings at specifed percentages recovered, or percentages recovered at specified thermometer readings.
Record all volumes in the graduated cylinder to the nearest 0.5 ml or 0.1 ml, and all thermometer readings to the nearest 0.5 °C or 0.1 °C as appropriate to the apparatus being used.
9.7.1 Group 0. In cases in which no specific data requirements have been indicated, record the initial boiling point, the final boiling point and thermometer readings at each 10 % multiple of volume recovered from 10 % to 90 % inclusive.
9.7.2 Groups 1, 2, 3 and 4. In cases in which no specific data requirements have been indicated, record the initial boiling point, the final boiling point or dry point, or both, and thermometer readings at 5 %, 15 %, 85 % and 95 % volume recovered, and at each 10 % multiple of volume recovered from 10 % to 90 % inclusive.
184.108.40.206 Group 4. When the high-range thermometer is used for testing kerosines, pertinent thermometer readings can be obscured by the centring device. If these readings are required, perform a second distillation in accordance with the requirements of group 3. In such cases, readings from the low-range thermometer are reported in place of the obscured high-range thermometer readings, and the test report shall so indicate. If, by agreement, the obscured readings are waived, the test report shall indicate this [see clause 13 d)].
220.127.116.11 When required to report the thermometer reading at a specified percent evaporated or recovered for a sample which has a rapidly changing slope of the distillation curve in the region of the specified percent evaporated or recovered reading, record thermometer readings at every 1 % (V/V) recovered. The slope is considered rapidly changing if the change in slope, C, of the data points described in 9.7.2 in that particular area is greater than 0.6 as calculated from the following equation:
C = [(T2 - T1)/(V2 - V1)] - [(T3 - T2)/(V3 - V2)]
T1 is the thermometer reading, in degrees Celsius, at the volume percent recorded one reading prior to that in question;
T2 is the thermometer reading, in degrees Celsius, at the volume percent recorded in question;
T3 is the thermometer reading, in degrees Celsius, at the volume percent recorded following that in question;
V1 is the volume percent recorded one reading prior to that in question;
V2 is the volume percent recorded in question;
V3 is the volume percent recorded following that in question.
9.8 When the residual liquid in the distillation flask is approximately 5 ml, make a final adjustment to the heat. To determine when the residual liquid in the distillation flask is approximately 5 ml, subtract the estimated loss from 93.5 ml to estimate the amount recovered in the receiver at that time. The time from the 5 ml of liquid residue in the distillation flask to the final boiling point shall be within the limits specified in Table 3. If this condition is not satisfied, repeat the test, with appropriate modification of the final heat adjustment.
If the actual loss differs by more than 2 ml from the estimated value, repeat the test.
NOTE Since it is extremely difficult to determine the amount of boiling residual liquid in the distillation flask, this is estimated from the amount of liquid recovered in the graduated cylinder at this time. The dynamic hold-up has been determined to be approximately 1.5 ml at this point, and thus with no losses, the amount of 5 ml in the distillation flask can be assumed to correspond to an amount of 93.5 ml in the receiving cylinder.
9.9 Observe and record the final boiling point, or dry point, or both, as required, and discontinue heating.
9.10 If the test is performed with a manual apparatus, and while the condenser tube continues to drain into the graduated cylinder, observe and note the volume of condensate, to the nearest 0.5 ml, at 2 min intervals until two successive observations agree. If an automated apparatus is used, then the apparatus shall continually observe the recovery volume until it changes by no more than 0.1 ml in 2 min. Measure this volume accurately, and record it, to the nearest 0.5 ml or 0.1 ml as appropriate to the apparatus being used, as percent recovery. If the distillation was previously discontinued under the conditions of a decomposition point, deduct the percent recovery from 100, report this difference as percent residue and loss, and omit the procedure described in 9.11.
9.11 After the distillation flask has cooled, and no more vapours are observed, disconnect the distillation flask from the condenser, pour its contents into the 5 ml graduated cylinder (5.7.2), and with the distillation flask suspended over the 5 ml graduated cylinder, allow the flask to drain until no appreciable increase in volume of the liquid in the 5 ml graduated cylinder is observed. Measure and record the volume in the graduated cylinder, to the nearest 0.1 ml, as percent residue.
NOTE If boiling chips were added, care should be taken to avoid their inclusion in this volume.
9.11.1 If the 5 ml graduated cylinder does not have graduations below 1 ml, and the volume of liquid is less than 1 ml, prefill the graduated cylinder with 1 ml of heavy oil to obtain a better reading of the volume of residue.
9.11.2 For group 0 samples, cool the 5 ml graduated cylinder to 0 °C to 5 °C. Record the volume in the graduated cylinder, to the nearest 0.1 ml, as percent residue.
9.11.3 For group 1, 2, 3 and 4 samples, record the volume in the 5 ml graduated cylinder, to the nearest 0.1 ml, as percent residue.
9.11.4 For group 4 products, examine the condenser arm and the side arm of the distillation flask for waxy or solid deposits. If found, repeat the test, adjusting the temperature of the condenser bath upwards within the range specified in Table 3.
9.12 If only the percent evaporated or percent recovered at a predetermined corrected thermometer reading is required, the procedure shall be modified as described in annex B.
10.1 The percent total recovery is the sum of the percent recovery (9.10) and the percent residue (9.11). Deduct the percent total recovery from 100 to obtain the percent loss.
10.2 Correct thermometer readings to 101.3 kPa pressure. Obtain the correction, Tc, to be applied to each thermometer reading by means of the Sydney Young equation given below, or by reference to Table 4.
Tc = 0.0009(101.3 - pk)(273 + t)
pk is the barometric pressure prevailing at the time and location of the test, in kilopascals;
t is the observed thermometer reading, in degrees Celsius.
NOTE 1 The absolute value of the temperature correction is to be added to the observed thermometer reading if the barometric pressure is less than 101.3 kPa; it is to be subtracted if the barometric pressure is greater than 101.3 kPa.
NOTE 2 For absolute accuracy, observed barometric pressures should be corrected to 0 °C and standard gravity, to compensate for changes in the gravity of the earth with respect to latitude. These compensations are small, and would result in a further correction of less than 0.2 °C in boiling point in the most extreme case. Unless specifically requested, these compensations are not required.
NOTE 3 Thermometer readings are not corrected to 101.3 kPa when product definitions, specifications, or agreements between the parties involved indicate, specifically, that such correction is not required, or that correction shall be made to some other base pressure.
After applying the corrections and rounding each result to the nearest 0.5 °C or 0.1 °C as appropriate to the apparatus being used, use the corrected thermometer readings in all further calculations and reporting.
10.3 Correct the actual loss to 101.3 kPa pressure when the thermometer readings are corrected to 101.3 kPa pressure. Calculate the corrected loss, Lc, in percent volume, from the following equation:
Lc = 0.5 + (L - 0.5)/[1 + (101.3 - p)/800]
L is the percent loss calculated from test data, in percent volume;
p is the observed barometric pressure, in kilopascals.
NOTE Above equation has been derived from experimental data, which is referenced in ASTM D86-96 and later editions.
10.4 Calculate the corresponding corrected percent recovery, Rc, in percent volume, from the following equation:
Rc = R + (L - Lc)
R is the observed recovery, in percent volume;
L is the observed percent loss, in percent volume;
Lc is the corrected percent loss, in percent volume.
10.5 To report percentages evaporated at specified thermometer readings, add the observed percent loss to each of the observed percentages recovered at the specified thermometer readings, and report these results as the respective percentages evaporated, that is:
Pe = Pr + L
Pe is the percentage volume evaporated;
Pr is the percentage volume recovered;
L is the observed percent loss, in percent volume.
10.6 To report thermometer readings at specified percentages evaporated, use either of the procedures given in 10.6.1 or 10.6.2, and indicate on the test report whether the graphical procedure or the arithmetical procedure has been used.
10.6.1 Arithmetical procedure
Deduct the observed distillation loss from each specified percentage evaporated in order to obtain the corresponding percentages recovered. Calculate each required thermometer reading, T, in degrees Celsius, using the following equation:
T = Ti + [(Th - Tl)(R - Rl)]/(Rh - Rl)
R is the percent volume recovered corresponding to the specified percent volume evaporated;
Rh is the percent volume recovered adjacent to, and higher than R;
Rl is the percent volume recovered adjacent to, and lower than R;
Th is the thermometer reading recorded at Rh, in degrees Celsius;
Tl is the thermometer reading recorded at Rl, in degrees Celsius.
Values obtained by the arithmetical procedure are affected by the extent to which the distillation graphs are non-linear. Intervals between successive data points shall, at any stage of the test, be no wider than the intervals indicated in 9.7. In no case shall a calculation be made that involves extrapolation.
10.6.2 Graphical procedure
Using graph paper with uniform subdivisions, plot each thermometer reading, corrected for barometric pressure, if required (see 10.2), against its corresponding percent volume recovered. Plot the initial boiling point at 0 % volume recovered. Draw a smooth curve connecting the points. For each specified percent volume evaporated, deduct the distillation loss, in order to obtain the corresponding percent volume recovered, and take from the graph the thermometer reading which this percent volume recovered indicates. Values obtained by graphical interpolation procedures are affected by the care with which the plot is made.
NOTE See annex C for numerical examples illustrating these arithmetical procedures.
10.6.3 Automated procedure
Distillations carried out with automated instruments which collect temperature-volume data and store them in memory, require neither of the procedures described in 10.6.1 and 10.6.2. Obtain the temperature directly from the database as that closest to and within 0.1 % (V/V) of the specified percent evaporated.