ISO/TS 23877-1:2023

Petroleum and related products from natural or synthetic sources - Determination of pour point - Part 1: Automated step-wise cooling method

This document specifies a method for determining the pour point of petroleum products by means of automated equipment, in which movement of the test specimen is detected using a step-wise cooling technique. A separate procedure suitable for the determination of the lower pour point of fuel oils, heavy lubricant base stock, and products containing residual fuel components is also described. The procedure described in this document is not suitable for crude oils. Test results from this method are determined in 3 °C testing intervals. NOTE Some equipment can also generate results at 1 °C testing intervals, which is an acceptable alternative procedure, but for which precision and bias have not been determined.

Produits pétroliers et connexes d'origine naturelle ou synthétique - Détermination du point d'écoulement — Partie 1: Méthode automatisée par refroidissement par paliers

General Information

• Status: Published
• Publication Date: 05-Jul-2023
• ICS: 75.080 - Petroleum products in general
• Technical Committee: ISO/TC 28 - Petroleum and related products, fuels and lubricants from natural or synthetic sources
• Drafting Committee: ISO/TC 28 - Petroleum and related products, fuels and lubricants from natural or synthetic sources
• Current Stage: 6060 - International Standard published
• Start Date: 06-Jul-2023
• Due Date: 06-May-2022
• Completion Date: 06-Jul-2023

Relations

• Consolidates: ISO/TS 21192:2019 - Electronic fee collection - Support for traffic management
• Effective Date: 06-Jun-2022
• Consolidated By: ISO/FDIS 20342-4 - Assistive products for tissue integrity when lying down - Part 4: Test methods for durability
• Effective Date: 14-Jan-2023

Overview

ISO/TS 23877-1:2023 specifies an automated step‑wise cooling method for the determination of the pour point of petroleum and related products from natural or synthetic sources. The technique uses automated equipment that detects specimen movement during step‑wise cooling to identify the lowest temperature at which the sample will still flow. Results are normally reported in 3 °C testing intervals (some instruments can generate 1 °C intervals as an alternative, though precision/bias for 1 °C results have not been determined). This procedure is not suitable for crude oils.

Key topics and technical requirements

• Principle: After controlled preheating, the sample is cooled in steps and monitored for flow; the lowest temperature at which movement is detected is the pour point.
• Automated detection: Instruments may use optical reflection, CCD cameras, thermal sensing, or ultrasonic sensors to detect movement (see Annex A).
• Test interval: Standard testing intervals are 3 °C; 1 °C outputs are an acceptable alternative but lack established precision data.
• Apparatus & probes:
  • Specified test jar dimensions and a contents mark for ~45 ml ±1 ml.
  • Sample temperature probe (e.g., PT100) with at least 0.1 °C resolution and 0.5 °C accuracy.
  • Cooling bath/jacket and anti‑moisture device to prevent contamination.
• Sample preparation:
  • Preheat rules differ by expected pour point: samples with pour points above −33 °C have different preheat temperatures than those at or below −33 °C.
  • If samples were heated >45 °C during transfer, allow 24 h at room temperature before testing.
• Calibration & verification:
  • Follow manufacturer calibration procedures.
  • Verify apparatus performance preferably at least twice a year using certified reference materials (ISO 17034); weekly in‑house checks (SQC) are recommended.
• Limitations: Not intended for crude oils; precision and bias for the new technique are still under study.

Applications and who uses it

• Quality control laboratories in refineries, petrochemical companies, fuel suppliers and lubricant manufacturers use this standard to assess low‑temperature flow properties.
• Instrument manufacturers use ISO/TS 23877-1 as a design and performance reference for automated pour‑point testers.
• Regulatory bodies and commodity specifiers reference the method for compliance testing of fuels, heavy lubricant base stocks and products containing residual fuel components.
• Practical benefits include improved repeatability through automation, reduced operator subjectivity compared with manual methods, and standardized reporting in 3 °C intervals.

Related standards

• ISO 3016 - manual pour point test (reference for traditional procedure)
• ISO 3170 / ISO 3171 - sampling of petroleum liquids
• ISO 17034 - certified reference material producers
• ISO 4259-4 - statistical quality control guidance

Keywords: ISO/TS 23877-1:2023, pour point determination, automated step-wise cooling method, petroleum products, pour point test, fuel oils, lubricant base stock, automated detection device.

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 23877-1
First edition
2023-07
Petroleum and related products
from natural or synthetic sources —
Determination of pour point —
Part 1:
Automated step-wise cooling method
Produits pétroliers et connexes d'origine naturelle ou synthétique -
Détermination du point d'écoulement —
Partie 1: Méthode automatisée par refroidissement par paliers
Reference number
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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ISO copyright office
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reagents and materials . 2
6 Apparatus . 2
7 Sampling . 3
8 Preparation of apparatus .3
9 Calibration .4
10 Verification of the performance of the apparatus . 4
11 Procedure . 4
12 Expression of results .5
13 Precision . 6
14 Test report . 6
Annex A (normative) Detection principles . 7
Bibliography .10
iii
Foreword
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bodies (ISO member bodies). The work of preparing International Standards is normally carried out
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electrotechnical standardization.
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described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
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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.
A list of all parts in the ISO 23877 series can be found on the ISO website.
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.
iv
Introduction
This document describes the determination of pour point by automated instruments that mirrors
ISO 3016 (which comprises a manual procedure only). This document is based on the techniques used
in the instruments available on the market in 2021.
This test method does not contain any precision at this stage. As this is a newly described technique,
no immediate precision or interim repeatability can be given either. At the time of publication,
an interlaboratory study was ongoing, the results of which will be taken into account in future
standardization activities.
v
TECHNICAL SPECIFICATION ISO/TS 23877-1:2023(E)
Petroleum and related products from natural or synthetic
sources — Determination of pour point —
Part 1:
Automated step-wise cooling method
WARNING — The use of this document can involve hazardous materials, operations and
equipment. This document does not purport to address all of the safety problems associated
with its use. It is the responsibility of the users of this document to take appropriate measures
to ensure the safety and health of personnel prior to the application of this document, and to
determine the applicability of any other restrictions.
1 Scope
This document specifies a method for determining the pour point of petroleum products by means of
automated equipment, in which movement of the test specimen is detected using a step-wise cooling
technique.
A separate procedure suitable for the determination of the lower pour point of fuel oils, heavy lubricant
base stock, and products containing residual fuel components is also described.
The procedure described in this document is not suitable for crude oils.
Test results from this method are determined in 3 °C testing intervals.
NOTE Some equipment can also generate results at 1 °C testing intervals, which is an acceptable alternative
procedure, but for which precision and bias have not been determined.
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 3170, Petroleum liquids — Manual sampling
ISO 3171, Petroleum liquids — Automatic pipeline sampling
ISO 17034, General requirements for the competence of reference material producers
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
pour point
lowest temperature at which a sample of petroleum product will continue to flow when it is cooled
under specified standard conditions
3.2
no-flow point
temperature of the test specimen at which a wax crystal structure or viscosity increase, or both,
impeding movement of the surface of the test specimen under specified standard conditions
4 Principle
After preliminary heating, the sample is cooled at a specified rate and examined at intervals of 3 °C for
flow characteristics. The lowest temperature at which movement ("pour" or "flow") of the sample is
detected, by the automated equipment, is recorded as the pour point.
5 Reagents and materials
5.1 Certified reference materials (CRM), from suppliers in accordance with ISO 17034.
6 Apparatus
6.1 Test jar, cylindrical, of clear glass, flat-bottomed, 33,2 mm to 34,8 mm outside diameter and
110 mm to 125 mm in height. The test jar shall have an inside diameter of 30,0 mm to 32,4 mm, with the
constraint that the wall thickness be no greater than 1,6 mm.
The jar shall be marked with a line to indicate a contents level, corresponding to a volume of 45 ml ± 1 ml.
6.2 Sample temperature probe, cylindrical, vertical in the test jar and plunged in the sample, depth
and location specified by the manufacturer of the testing device (see also References [3] and [4]).
A thermometer with digital display (e.g. PT100) shall be used for measuring the sample temperature
with a resolution of at least 0,1 °C and an accuracy of at least 0,5 °C (see Figure 1).
NOTE The exact location of the probe depends on the equipment design manufacturer.
6.3 Anti-moisture device, to close the test jar and bath, preventing the introduction of any moisture.
6.4 Jacket (test jar container), watertight, cylindrical metal, flat-bottomed, dimensions as per the
manufacturer of the testing device. It shall be supported in a vertical position in the cooling device
(6.7), and shall be capable of being cleaned.
6.5 Disc (optional, depending on the design of the equipment), made of any insulating material
(for example cork or felt) approximately 6 mm in thickness, to fit loosely inside the jacket to maintain
the test jar and avoid any direct contact with the jacket.
6.6 Gasket (optional, depending on the design of the equipment), ring form, app
...