oSIST prEN ISO 3405:2025

SLOVENSKI STANDARD
01-september-2025
Naftni in sorodni proizvodi iz naravnih ali sintetičnih virov - Določanje
destilacijskih značilnosti pri atmosferskem tlaku (ISO/DIS 3405:2025)
Petroleum and related products from natural or synthetic sources - Determination of
distillation characteristics at atmospheric pressure (ISO/DIS 3405:2025)
Mineralölerzeugnisse und verwandte Produkte mit natürlichem oder synthetischem
Ursprung - Bestimmung des Destillationsverlaufes bei Atmosphärendruck (ISO/DIS
3405:2025
Produits pétroliers et connexes d'origine naturelle ou synthétique - Détermination des
caractéristiques de distillation à pression atmosphérique (ISO/DIS 3405:2025)
Ta slovenski standard je istoveten z: prEN ISO 3405
ICS:
75.080 Naftni proizvodi na splošno Petroleum products in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 3405
ISO/TC 28
Petroleum and related products
Secretariat: NEN
from natural or synthetic sources —
Voting begins on:
Determination of distillation
2025-06-03
characteristics at atmospheric
Voting terminates on:
pressure
2025-08-26
Produits pétroliers et connexes d'origine naturelle ou
synthétique — Détermination des caractéristiques de distillation
à pression atmosphérique
ICS: 75.160.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
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Reference number
ISO/DIS 3405:2025(en)
DRAFT
ISO/DIS 3405:2025(en)
International
Standard
ISO/DIS 3405
ISO/TC 28
Petroleum and related products
Secretariat: NEN
from natural or synthetic sources —
Voting begins on:
Determination of distillation
characteristics at atmospheric
Voting terminates on:
pressure
Produits pétroliers et connexes d'origine naturelle ou
synthétique — Détermination des caractéristiques de distillation
à pression atmosphérique
ICS: 75.160.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
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Published in Switzerland Reference number
ISO/DIS 3405:2025(en)
ii
ISO/DIS 3405:2025(en)
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Apparatus . 3
5.1 General .3
5.2 Distillation flasks .3
5.3 Condenser tube and cooling bath.4
5.4 Metal shield or enclosure for flask (manual apparatus only) .4
5.5 Heat source(s) .8
5.6 Flask-support .8
5.7 Graduated cylinders . . .9
5.8 Temperature measurement system .10
5.9 Centring device .10
5.10 Barometer .10
6 Samples and sampling . .12
6.1 Sample grouping . 12
6.2 Sample maintenance prior to testing . 13
6.2.1 General . 13
6.2.2 Groups 1 and 2 . 13
6.2.3 Groups 3 and 4 . 13
6.3 Removing water from sample .14
6.3.1 General .14
6.3.2 Groups 1 and 2 .14
6.3.3 Groups 3 and 4 .14
7 Preparation of apparatus . 14
8 Apparatus verification .16
8.1 Level follower .16
8.2 Electronic temperature-measurement devices.16
8.3 Electronic pressure measuring device .17
9 Procedure — Manual apparatus . 17
10 Procedure — Automated apparatus .20
11 Calculations .21
12 Expression of results .24
13 Precision (Manual Apparatus) .24
13.1 General .24
13.2 Repeatability . 25
13.3 Reproducibility . 26
14 Precision (automated apparatus) .26
14.1 General . 26
14.2 Repeatability .27
14.3 Reproducibility .27
14.4 Bias . 28
14.4.1 Bias . 28
14.4.2 Relative bias. 28
15 Test report .28
Annex A (normative) Thermometer specifications .29

iii
ISO/DIS 3405:2025(en)
Annex B (normative) Procedure for verification of dynamic response of the temperature
measurement system .30
Annex C (normative) Determination of specified distillation data .32
Annex D (informative) Examples of data calculations .34
Annex E (informative) Emulation of lag time and emergent-stem errors .37
Annex F (informative) Examples of a test report .38
Bibliography .40

iv
ISO/DIS 3405:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent
rights identified during the development of the document will be in the Introduction and/or on the ISO list of
patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 28, Petroleum and related products, fuels and
lubricants from natural or synthetic sources.
This sixth edition cancels and replaces the fifth edition (ISO 3405:2019), which has been technically revised.
The main changes compared to the previous edition are as follows:
— Annex B replaced with ASTM D86 Procedure for verification of dynamic response of the temperature
measurement system. Relevant information added in appropriate sections and annexes. Permission for
usage of the alignment information for Annex B was granted by ASTM June 2024.
— 5.8.2 include use of verified electronic temperature devices as referee
— 8.2 revised procedures on verification of temperature measurement
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
DRAFT International Standard ISO/DIS 3405:2025(en)
Petroleum and related products from natural or synthetic
sources — Determination of distillation characteristics at
atmospheric pressure
WARNING — The use of this document can involve hazardous materials, operations and equipment.
This document does not purport to address all the safety problems associated with its use. It is the
responsibility of users of this document to take appropriate measures to ensure the safety and
health of personnel prior to the application of the standard, and to determine the applicability of any
other restrictions for this purpose.
1 Scope
This document specifies a laboratory method for the determination of the distillation characteristics of
light and middle distillates derived from petroleum and related products of synthetic or biological origin
with initial boiling points above 0 °C and end-points below approximately 400 °C, utilizing either manual or
automated equipment. Light distillates are typically automotive engine petrol, automotive engine ethanol
[4]
fuel blends with up to 85 % (V/V) ethanol, and aviation petrol. Middle distillates are typically aviation
turbine fuel, kerosene, diesel, diesel with up to 30 % (V/V) FAME, burner fuel, and marine fuels that have no
appreciable quantities of residua.
NOTE For the purposes of this document, the term “% (V/V)” is used to represent the volume fraction of a
material.
The distillation (volatility) characteristics of hydrocarbons and related products of synthetic or biological
origin have an important effect on their safety and performance, especially in the case of fuels and solvents.
The boiling range gives important information on composition and behaviour during storage and use, and
the rate of evaporation is an important factor in the application of many solvents. Limiting values to specified
distillation characteristics are applied to most distillate petroleum product and liquid fuel specifications in
order to control end-use performance and to regulate the formation of vapours which may form explosive
mixtures with air, or otherwise escape into the atmosphere as emissions (VOC).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 918, Volatile organic liquids for industrial use — Determination of distillation characteristics
ISO 3170, Petroleum liquids — Manual sampling
ISO 3171, Petroleum liquids — Automatic pipeline sampling
ISO 4788, Laboratory glassware — Graduated measuring cylinders
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp

ISO/DIS 3405:2025(en)
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
decomposition point
thermometer reading (corrected) which coincides with the first indications of thermal decomposition of the
liquid in the flask
Note 1 to entry: Characteristic indications of thermal decomposition are an evolution of fumes and erratic thermometer
readings which usually show a decided decrease after any attempt has been made to adjust the heat.
3.2
dry point
thermometer reading (corrected) that is observed at the instant the last drop of liquid evaporates from the
lowest point in the flask, any drops or film of liquid on the side of the flask or on the thermometer being
disregarded
Note 1 to entry: The end-point (final boiling point), rather than the dry point is intended for general use. The dry
point can be reported in connection with special purpose naphthas, such as those used in the paint industry. Also, it
is substituted for the end-point (final boiling point) whenever the sample is of such a nature that the precision of the
end-point cannot consistently meet the precision requirements given in Clauses 13 or 14.
3.3
final boiling point
end-point maximum thermometer reading (corrected) obtained during the test
Note 1 to entry: This usually occurs after evaporation of all liquid from the bottom of the flask.
3.4
initial boiling point
thermometer reading (corrected) that is observed at the instant that the first drop of condensate falls from
the lower end of the condenser tube
3.5
percent evaporated
sum of the percent recovered and the percent loss
3.6
percent loss
calculated amount of uncondensed material
Note 1 to entry: Sometimes called “front-end loss”; this is the amount of uncondensed material lost in the initial stages
of the distillation.
3.7
corrected loss
percent loss corrected for barometric pressure
3.8
percent recovered
volume of condensate observed in the receiving cylinder at any point in the distillation, expressed as a
percentage of the charge volume, in connection with a simultaneous temperature reading
3.9
percent recovery
maximum percent recovered, as observed in accordance with 9.10 or 10.10
3.10
percent residue
volume of residue measured in accordance with 9.11 or 10.11, and expressed as a percentage of the charge volume
3.11
percent total recovery
combined percent recovery and residue in the flask, as determined in accordance with 11.1

ISO/DIS 3405:2025(en)
3.12
thermometer reading
temperature recorded by the sensor of the saturated vapour measured in the neck of the flask below the
vapour tube, under the specified conditions of this test
3.13
temperature reading
thermometer or temperature-measurement device reading (3.12) which is corrected to 101,3 kPa standard
pressure
3.14
emergent stem effect
offset in temperature reading caused by the use of a total immersion mercury-in-glass thermometer in the
partial immersion mode
Note 1 to entry: The emergent part of the mercury column is at a lower temperature than the immersed portion,
resulting in a lower temperature reading than that obtained when the thermometer was completely immersed for
calibration.
3.15
temperature lag
offset in temperature reading between a mercury-in-glass thermometer and an electronic temperature-
measurement device, caused by the different response time of the systems involved
3.16
check standard
material having an accepted reference value used to determine the accuracy of a measurement system
4 Principle
The sample is assigned into one of four groups based on its composition and expected volatility
characteristics, each group defining the apparatus arrangement, condenser temperature and operational
variables. A 100 ml test portion is distilled under the specified conditions appropriate to the group into
which the sample falls, and systematic observations of thermometer readings and volumes of condensate
recovered are made. The volume of the residue in the flask is measured, and the loss on distillation recorded.
The thermometer readings are corrected for barometric pressure, and the data are then used for calculations
appropriate to the nature of the sample and the specification requirements.
5 Apparatus
5.1 General
Typical assemblies of the manual apparatus are shown in Figures 1 and 2. In addition to the basic components
described in Clause 5, automated apparatus are equipped with a system to measure and automatically
record the vapour temperature and the associated recovered volume in the receiving cylinder.
Automated equipment manufactured from 1999 onwards shall be equipped with a device to automatically
shut down power to the unit and to spray an inert gas or vapour in the chamber where the distillation flask
is mounted in the event of fire.
NOTE Some causes of fires are breakage of the distillation flask, electrical shorts, and foaming and spilling of
liquid sample through the top opening of the flask.
5.2 Distillation flasks
The distillation flasks shall have a capacity of 125 ml and be constructed of heat-resistant glass, according to
the dimensions and tolerances shown in Figure 3.

ISO/DIS 3405:2025(en)
For tests specifying the dry point, especially selected flasks with bottoms and walls of uniform thickness
are recommended.
5.3 Condenser tube and cooling bath
5.3.1 Typical types of condenser and cooling bath are illustrated in Figures 1 and 2.
Other types of apparatus may be used, provided that the test results obtained by their use are such as to
correlate with the results obtained with those illustrated, and to satisfy the precision criteria given in
Clauses 13 or 14.
5.3.2 The condenser shall be made of seamless non-corrosive metal tubing, 560 mm ± 5 mm in length,
with an outside diameter of 14 mm and a wall thickness of 0,8 mm to 0,9 mm.
NOTE Brass or stainless steel are suitable materials.
5.3.3 The condenser shall be set so that 393 mm ± 3 mm of the tube is in contact with the cooling medium,
with 50 mm ± 3 mm outside the cooling bath at the upper end, and 114 mm ± 3 mm outside at the lower
end. The portion of tube projecting at the upper end shall be set at an angle of 75° ± 3° to the vertical. The
portion of the tube inside the cooling bath shall be either straight or bent in any suitable continuous smooth
curve. The average gradient shall be 15° ± 1° with respect to the horizontal, and no 100 mm section shall
have a gradient outside a 15° ± 3° range. The projecting lower portion of the condenser tube shall be curved
downward for a length of 76 mm and the lower end cut off at an acute angle. Provisions shall be made to
enable the flow of distillate to run down the side of the receiving cylinder. Figure 4 gives an illustration of
the lower end of the condenser tube.
The flow of distillate down the side of the graduated cylinder can be accomplished either by using a drip-
deflector which is inserted in the receiver, or by having the downward length of the condenser tube curve
slightly backwards so as to ensure contact with the wall of the receiving cylinder at a point 25 mm to 32 mm
below the top of the receiving cylinder when it is in position to receive distillate.
5.3.4 The volume and design of the cooling bath will depend on the cooling medium employed. The cooling
capacity of the bath shall be adequate to maintain the required temperature for the desired condenser
performance. A single cooling bath may be used for several condenser tubes.
5.4 Metal shield or enclosure for flask (manual apparatus only)
Shields shall be provided to protect the operator from damage from the unit during operation, and to protect
the distillation flask from draughts. They shall allow easy access to the distillation during operation, and be
provided with at least one window to observe the dry point at the end of the distillation.
NOTE 1 A typical shield for a unit fitted with a gas burner would be 480 mm high, 280 mm long and 200 mm wide,
made of sheet metal approximately 0,8 mm in thickness (see Figure 1).
NOTE 2 A typical shield for a unit fitted with an electric heater would be 440 mm high, 200 mm long and 200 mm
wide, made of sheet metal approximately 0,8 mm in thickness (see Figure 2).

ISO/DIS 3405:2025(en)
Key
1 cooling bath
2 air vents
3 burner
4 shield
5 heat-resistant boards
6 distillation flask
7 thermometer
8 bath cover
9 blotting paper
10 support
11 graduated cylinder
12 gas line
Figure 1 — Apparatus assembly using a gas burner

ISO/DIS 3405:2025(en)
Key
1 receiving cylinder
2 blotting paper
3 thermometer
4 distillation flask
ISO/DIS 3405:2025(en)
5 flask-support board
6 electric heating element
7 flask-support platform
8 flask-adjusting knob
9 indicating dial
10 switch
11 open bottom shield
12 cooling bath
13 condenser tube
14 shield
Figure 2 — Apparatus assembly using an electric heater
Dimensions in millimetres
Key
1 19/22 neck or 19/26 neck
a
Reinforcing bead.
b
Fire polished.
Figure 3 — 125 ml flasks — Alternative neck designs

ISO/DIS 3405:2025(en)
Dimensions in millimetres
Figure 4 — Lower end of condenser tube
5.5 Heat source(s)
5.5.1 Gas burner (see Figure 1), capable of bringing over the first drop from a cold start within the time
specified, and continuing the distillation at the specified rate. A sensitive regulating valve and gas pressure
governor to give complete control of heating shall be provided.
5.5.2 Electric heater (see Figure 2), of low heat retention and adjustable from 0 W to 1 000 W.
5.6 Flask-support
5.6.1 Type 1 for use with gas burner (see Figure 1). Either a ring support of the ordinary laboratory
type, 100 mm or larger in diameter, supported on a stand inside the shield, or a platform adjustable from the
outside of the shield shall be used.
The flask support board shall be constructed of ceramic or other heat-resistant material, 3 mm to 6 mm in
thickness and shall have a central opening conforming to the dimensions given in Table 2. The flask support
board shall be of sufficient dimension to ensure that thermal heat to the flask only comes from the central
opening and that extraneous heat to the flask other than through the central opening is minimized. The
flask-support board may be moved slightly in accordance with the directions for positioning the distillation
flask so that direct heat is applied to the flask only through the opening in this board. The position of the
flask is set by adjusting the length of the side-arm inserted into the condenser.
5.6.2 Type 2 for use with an electric heater (see Figure 2). The flask-support is a platform on top of the
electric heater and adjustable from the outside of the shield. The flask support board described in 5.6.1 is
mounted on this support. Provision shall be made for moving the upper (flask-support) board slightly in the
horizontal plane to ensure that direct heat is applied only through the specified opening in this board. The
flask-support assembly shall be able to move vertically to ensure contact of the flask-support board with
the bottom of the distillation flask during the distillation, and to allow for easy mounting and removal of the
distillation flask from the unit.

ISO/DIS 3405:2025(en)
5.7 Graduated cylinders
5.7.1 Receiving cylinder, of 100 ml ± 1,0 ml capacity, nominally in accordance with ISO 4788. It shall
be graduated at intervals of 1 ml beginning at least at the 5 ml mark and have a graduation at the 100 ml
mark. The shape of the base shall be such that the receiver does not topple when placed empty on a surface
inclined at an angle of 13° to the horizontal. Construction details and tolerances for the graduated cylinder
are shown in Figure 5.
Dimensions in millimetres
Key
1 fire polished top end
Figure 5 — 100 ml receiving cylinder (tolerance ±1,0 ml)
For automated apparatus, the receiving cylinder shall conform to the specifications of the manufacturer of
the distillation apparatus. Receiving cylinders for use in automated units shall have a 100 ml mark and may
also have a metal base.
ISO/DIS 3405:2025(en)
If required, the receiving cylinder shall be either immersed in a cooling bath containing cooling liquid, such
as a tall-form beaker of clear glass or transparent plastic, up to above the 100 ml graduation line, or placed
in a thermostatically controlled air-circulation chamber.
5.7.2 Residue cylinder, of 5 ml capacity, generally in accordance with ISO 4788.
5.8 Temperature measurement system
5.8.1 Thermometers, if used, shall be of the mercury-in-glass type, nitrogen filled, graduated on the stem
and enamel backed, and shall conform to the specifications given in Annex A.
CAUTION — Under certain test conditions, the bulb of the thermometer can be 28 °C above the
temperature indicated, and at an indicated temperature of 370 °C, the temperature of the bulb
is approaching a critical range in the glass. It is thus strongly recommended that distillation
temperature readings above 370 °C are avoided, but in those cases where thermometers have been
exposed to observed temperature readings above 370 °C, they shall not be re-used without checking
their ice point to verify calibration.
5.8.2 Electronic temperature-measurement devices, if used, shall exhibit the same temperature lag,
emergent stem effect and accuracy as the equivalent mercury-in-glass thermometer.
To simulate the temperature lag and emergent stem effect of a mercury-in-glass thermometer, the circuitry
and/or the algorithms used for the electronic system shall take this fact into account, see Annex E.
Alternatively, place the sensor in a casing with the tip covered, so that the assembly, because of its adjusted
thermal mass and conductivity, has a temperature lag and emergent stem effect similar to that of mercury-
in-glass thermometers.
In case of dispute, unless otherwise agreed, the referee test shall be carried out using the specified mercury-
in-glass thermometers, or when using an electronic temperature measurement system which has been
verified through the procedures described in 8.2 and Annex B.
5.9 Centring device
The temperature sensor shall be fitted through a snug-fitting device designed for mechanically centring
the sensor in the neck of the distillation flask without vapour leakage. The use of a cork or silicone rubber
stopper with a hole drilled through the centre is not acceptable for this purpose. Examples of acceptable
centring devices are shown in Figures 6 and 7.
When running tests by the manual method, products with a low initial boiling point can have one or more
temperature readings obscured by the centring device.
Centring devices not shown in Figures 6 and 7 are also acceptable provided they position and hold the
temperature sensor in the middle of the neck of the distillation flask.
5.10 Barometer
The barometer shall be capable of measuring atmospheric pressure with an accuracy of 0,1 kPa or better, at
the same elevation relative to sea level as the apparatus in the laboratory. Do not take readings from aneroid
barometers that are pre-corrected to give sea level pressures.
The barometer should ideally be located in the room in which the distillation is carried out.

ISO/DIS 3405:2025(en)
Key
1 O-ring
a
Screwcap.
b
Knurled knob.
c
Cone male NS 19/26.
Figure 6 — PTFE centring device for ground-glass joint

ISO/DIS 3405:2025(en)
Key
1 single O-ring Viton or perfluoro elastomer
2 compression nut (PTFE)
3 PTFE body
4 double O-rings Viton or perfluoro elastomer
5 compression O-ring
6 compression nut
7 thermometer or Pt 100 probe
8 neck of distilling flask
a
Cone-shaped for perfect centring in neck of distillation flask.
b
Drilled out to fit Pt 100 probe.
c
Compression without O-ring.
d
Threads.
Figure 7 — Two illustrative centring device designs for straight-bore neck
6 Samples and sampling
6.1 Sample grouping
Determine the nature of the product to be sampled and place it in the appropriate group according to Table 1,
which also gives general guidance on sampling conditions.

ISO/DIS 3405:2025(en)
6.2 Sample maintenance prior to testing
6.2.1 General
Unless otherwise specified, sampling shall be carried out by the procedures described in ISO 3170 or
ISO 3171, bearing in mind the special conditions described in Table 1. Maintain samples prior to testing at
the specified temperatures given in Table 1, away from sources of direct heat or sunlight.
6.2.2 Groups 1 and 2
Collect the sample in a container previously cooled to below 10 °C, when necessary. Condition the container
preferably by immersing it in the liquid, where possible, and discarding the first sample. Where immersion
is not possible, the sample shall be drawn off into the previously cooled container in such a manner that
agitation is kept at a minimum. Close the container immediately with a tight-fitting stopper, and place the
sample in an ice bath or refrigerator to maintain the sample below the specified temperature. Maintain the
sample below 10 °C prior to testing, and preferably store at or below this temperature. Where maintenance
and/or storage at below 10 °C is not possible or practicable, a temperature up to 20 °C is acceptable provided
that the sample is always conditioned to a temperature below 10 °C before the container is opened.
6.2.3 Groups 3 and 4
Maintain the sample at ambient temperature. If the sample is not fluid at ambient temperature, maintain it
at a temperature of 9 °C to 21 °C above its pour point. Shake the sample vigorously prior to subsampling to
ensure homogeneity, and disregard the temperature range shown in Table 2 for the receiving cylinder. Prior
to analysis, heat the receiving cylinder to approximately the same temperature as the sample, and pour the
heated test portion precisely to the 100 ml mark. Transfer the test portion as rapidly and completely as
possible to the distillation flask.
CAUTION — A tightly-sealed, full, cold container of sample is likely to break if heated.
Table 1 — Sample groups and sampling conditions
Group number 1 2 3 4
Typical sample type Gasoline Gasoline Wide-cut Kerosene/
aviation fuel gas oil
Vapour pressure ≥65,5 <65,5 <65,5 <65,5
(DVPE), kPa
Initial boiling point — — ≤100 >100
(IBP), °C
Final boiling point ≤250 ≤250 >250 >250
(FBP), °C
Temperature of sample <10 — — —
bottle, °C
a a
Temperature of sample ≤10 ≤10 Ambient Ambient
at sampling, °C
b b
Temperature of stored <10 <10 Ambient Ambient
sample, °C
If sample is wet Resample or dry Resample or dry Dry Dry
(Reference) (6.3.2) (6.3.2) (6.3.3) (6.3.3)
a
Samples shall always be at 9 °C to 21 °C above their pour point if not fluid at ambient temperature.
b
When no facilities available for storage below 10 °C, the sample may be stored below 20 °C provided the container is tightly
sealed. See 6.2.2.
ISO/DIS 3405:2025(en)
6.3 Removing water from sample
6.3.1 General
Samples of materials that are visibly hazy (suspended water) or are suspected of containing water are not
suitable for testing.
6.3.2 Groups 1 and 2
If the sample is not dry, obtain another sample for testing that is free from suspended water. If such a sample
cannot be obtained, add a sufficient amount of anhydrous sodium sulfate or other suitable drying agent to
the sample maintained at 0 °C to 10 °C, and physically remove the water by shaking. Once the sample shows
no visible signs of water, use a decanted portion of the sample, maintained at 0 °C to 10 °C, for the analysis.
Record that the sample has been dried by desiccant.
Data from a round-robin exercise show that suspended water in hazy samples in group 1 and group 2 may be
removed by the above procedure without statistically affecting the results of the test.
6.3.3 Groups 3 and 4
In cases where a water-free sample is not practical, remove the suspended water by shaking the sample
with anhydrous sodium sulphate or another suitable drying agent, and separate it from the drying agent by
decantation.
7 Preparation of apparatus
7.1 Refer to Table 2 and prepare the apparatus by choosing the appropriate distillation flask, temperature-
measurement system and flask-support board as directed for the indicated group. If gas heating is used,
use a Type 1 flask-support (5.6.1); if electric heating is used, use a Type 2 flask-support (5.6.2). Bring the
temperature of the receiving cylinder, the flask, the temperature sensor and the cooling bath to the indicated
temperature.
7.2 Make any necessary provisions so that the temperature of the cooling bath and receiving cylinder will
be maintained at their specified temperatures. The receiving cylinder shall be positioned in a bath such that
either the liquid level is at least as high as the 100 ml mark, or the entire receiving cylinder is surrounded by
an air-circulation chamber.
For groups 1, 2 and 3, use suitable media for low temperature baths such as chopped ice and water,
refrigerated brine and refrigerated ethylene glycol.
For group 4, use suitable media for ambient and higher bath temperatures such as cold water, hot water and
heated ethylene glycol.
7.3 Remove any residual liquid in the condenser tube by swabbing with a piece of soft, lint-free cloth
attached to a cord or wire.
7.4 For samples in groups 1, 2 and 3, fit a low-range temperatu
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