HFRR test

Test instrument: HFRR test instrument
Sample quantity: 10 ml
Unit: Diameter of a wear dome in µm
Analysis for: diesel fuel
Brief description: This instrument is a vibration friction wear tester. The HFRR value (high frequency reciprotating rig) is determined by pressing a 6 mm steel ball onto a steel plate with a defined hardness and surface roughness with a force of 2 Newton and at a frequency of 50 Hz, grinding it over the plate with a horizontal displacement of 1 mm. The ball is in a liquid bath of the fuel to be tested. Due to the relative movement and the pressure, a wear dome is formed. The diameter of this wear dome is given as the HFRR value.

Since low-sulphur diesel fuel has been introduced throughout Europe and for this purpose the fuel has to be desulphurised to a greater or lesser extent depending on its origin, it has been established that this has also reduced the lubricity of the fuel.

The test gives a statement about the lubricity of diesel fuels, which should protect against wear, especially in fuel-lubricated diesel injection pumps. The smaller the wear dome produced in the test, the smaller the HFRR value and the better the lubricity.

Underlying test standard: EN ISO 12156-1