Test equipment

Predict DRF (Direct Read Ferrograph)

Sample size

20ml (recommended), 10ml (minimum)





Test methodology

The DRF operates by flowing lubricant through a precipitator tube over a strong magnet. DR works by collecting ferrous particles on two light sources over a strong magnet and measuring the amount of blocked light.

The results received are ferrous large (DL) greater than five microns in size and ferrous small (DS) which are those particles less than five microns in size.

The DL and DS results are used in specific formulas to help determine the Wear Particle Count (WPC) and Percentage Large Particles (PLP).

Notes (application)

DRF is a non-destructive technique to evaluate ferrous concentration within the oil.

The instrument also establishes the baseline wear level for any piece of equipment. Any sudden increase in the wear trend level alerts the user to potential problems prompting preventive actions. As a result, trending is important to accurately analyse the values obtained.

Suitable for systems

This test is particularly useful for gearbox and other components prone to wear mechanisms that produce large quantities of ferrous particle.

Appropriate for every lubrication type (as long as a representative sampling location is available)

Also suitable for Grease samples.

DR ferrography needs to be complimented with system and component information, sampling point location and trending for a meaningful analysis.