Sediment and Sludge

This test distinguishes between sediment and total sludge that is oil insoluble sludge plus sludge which is precipitated by adding heptanes. Solid matter comprises insoluble oxidation or degradation products of insulating materials, fibres of various origins, carbon, metallic oxides, etc, arising from the conditions of service of the equipment. The presence of solid particles may reduce the electric strength of the oil and, in addition, deposits may hinder heat transfer, thus promoting further deterioration of insulation. Sludge consists of products formed at an advanced stage of oxidation and is forewarning of sludge deposits in the equipment.