The Bacharach True Spot Smoke Test Kit determines efficient combustion and is internationally recognized as the standard method for evaluating smoke density in the flue gases from distillate fuels. Too much smoke is one of the most common causes of excessive fuel usage and expensive service requirements. That is precisely why the smoke test is an indispensable part of any oil burner service job; and with the True Spot, an accurate smoke reading takes less than a minute.