Ecol tests: Cold filter blocking temperature / Turbidity temperature

method description:

The fuel sample is cooled and aspirated through a pipette filter in standardised 1°C increments. The paraffin crystals emitted from the fuel reduce the fuel flow rate. When the pipette filling time exceeds 60 s, or the pipette emptying time is longer than the temperature drop time of 1°C, the temperature reading is considered to be the result of the cold filter blockage temperature determination.

The turbidity temperature is determined as the sample cools. The highest temperature at which a transparent fuel sample becomes opaque due to the release of paraffin crystals is determined.

interpretation of results:

The turbidity temperature is the temperature at which the crystallisation process of the paraffins contained in the fuel begins, which manifests itself as a characteristic turbidity.

The Cold Filter Plugging Point (CFPP) defines the limiting fuel application temperature at which both the amount of crystallised paraffin, prevents the flow of diesel through the fuel filter and causes it to block. Under real-world conditions, this situation results in the immobilisation of the unit and the need for service action.

The required CFPP value for standard diesel (summer, transitional and winter) is set out in the Regulation of the Minister of the Economy on quality requirements for liquid fuels.