apparatus which is exposed to a gas stream particularly to portions subjected to operating temperatures of about 100 u00b0 c when the coated portion of the electrical apparatus overheats the grease forms particles in the gas stream which are detected by a monitor the apparatus can then be shut down or its load reduced application_number US 95614378 A description the greases of this invention are either synthetic straight chain hydrocarbons synthetic diesters petroleum based branched hydrocarbons or mixtures of any of these the greases must decompose between about 60 u00b0 and about 200 u00b0 c and produce particles larger than about 25 a in order for the particles to be detected with presently existing monitors the synthetic diester preferably has the general formula str1 where n is an integer from 2 to 10 each r 1 is independently selected from str2 and mixtures thereof where x y is an integer from 2 to 20 and r 2 is selected from str3 and mixtures thereof where a b is an integer from 2 to 12 the petroleum based branched hydrocarbon is preferably either a paraffin base compound having the general formula where n is an integer from 4 to 35 or a naphthene base compound having the general formula where n is an integer from 2 to 20 and x is.