Overview
ISO/TS 23877-2:2024 - Petroleum and related products - Determination of pour point - Part 2: Automated linear cooling method - specifies an automated method for determining the pour point of petroleum products using linear cooling and automatic movement-detection. The Technical Specification covers equipment setup, calibration, verification, test procedure and result expression for automatic analysers that detect sample movement (optical, pressure or similar detection principles). It is intended for products from natural or synthetic sources but explicitly excludes crude oils.
Key topics and technical requirements
- Test principle: linear cooling of a pretreated sample with periodic checks for flow; the pour point is the lowest temperature at which flow is observed.
- Detection methods: automated detection devices (e.g., optical arrays, pressure sensing or pressure-pulsing systems) as outlined in Annex A.
- Testing intervals: results can be reported using 3 °C intervals (required for formats similar to ISO 3016) or 1 °C intervals (acceptable alternative; precision/bias not yet established).
- Preliminary heating:
- Samples with expected pour point > −33 °C: heat without stirring to 9 °C above expected pour point (or to 45 °C as specified).
- Samples with expected pour point ≤ −33 °C: heat without stirring to 45 °C.
- For lower pour point determinations (fuel oils, heavy lubricant base stocks, residual-containing products): an additional heating step to 105 °C with stirring may be required.
- Cooling profiles: manufacturer-specific profiles are used (examples include pressure pulsing, air pressure or pressure sensing modes with defined cooling rates).
- Calibration and verification:
- Use certified reference materials (CRMs) in accordance with ISO 17034.
- Manufacturer calibration instructions must be followed.
- Performance verification recommended at least twice yearly; frequent checks (e.g., weekly) with in-house SQC or secondary reference materials per ISO 4259-4.
- Sampling and reporting: sampling per ISO 3170/ISO 3171; test reports must reference ISO/TS 23877-2:2024 and include test conditions, interval used, any deviations and the result (add 3 °C or 1 °C to the recorded no-flow temperature per Clause 12).
Applications
- Routine pour point testing in quality control laboratories of petroleum refineries, fuel producers and lubricant manufacturers.
- Determination of upper and lower pour points for fuel oils, heavy lubricant base stocks and products containing residual fuel components.
- Automated, higher-throughput pour point measurement where reproducibility, traceability and integration with SQC systems are needed.
Who should use this standard
- QC chemists and laboratory managers in petroleum, fuels and lubricant industries
- Instrument manufacturers and service engineers for automated pour point analysers
- Standards and compliance personnel implementing pour point testing protocols
Related standards
- ISO 3170 - Petroleum liquids - Manual sampling
- ISO 3171 - Petroleum liquids - Automatic pipeline sampling
- ISO 17034 - Competence of reference material producers
- ISO 4259-4 - Statistical quality control guidance (intralaboratory)
- ISO 3016 - (format reference for interval requirements)
Keywords: ISO/TS 23877-2:2024, pour point, automated linear cooling, pour point determination, petroleum products, fuel oils, lubricant base stock, automated pour point testing.