Soil is composed of living organisms, water, carbonates, carbon containing material, decomposing matter and much more. To determine how much one of these soil components make up the entire soil mass, the LOI procedure is implemented. Initially, the researcher will take the mass of the sample prior to LOI and then place the sample into a heating device. Depending on what the researcher is trying to determine in the soil, the temperature of the device can be set to the corresponding temperature. The soil sample is kept at this temperature for an extended period of time after which it is removed and allowed to cool down before re-weighing the sample. The amount of mass lost after the LOI treatment is equal to the mass of the component the researcher is trying to determine. The typical set of materials needed to use LOI include: a high precision mass balance, a drying oven, temperature controlled furnace, preheated crucibles and soil sample from the location of interest.
There are many ways to properly utilize loss on ignition for scientific research. A soil sample left overnight in a drying oven at 100 °C would have its water content completely evaporated by morning. This could allow the researchers to determine the amount of water initially in the soil sample and its porosity by comparing the change in weight of the sample before and after the evaporation. This new weight of the sample is called the dry weight and its previous weight is called the wet weight.