Loss on Drying / Ignition

Definition of Loss on Ignition:

The most common loss on ignition test is simple ‘Ashing’

The Carbolite ABA or asphalt binder analyser is a furnace that is designed to carry out proportional determinations of asphalt and bitumen binders in samples of HMA or hot mix asphalt. It is compatible with the AASHTO T 308-10, ASTM D6307-10 and BS EN 12697-39:2012 test methods.

Definition of Loss on Drying:

This is a widely used test method to determine the moisture content of a sample, although occasionally it may refer to the loss of any volatile matter from the sample. Therefore this method does not usually refer to molecularly bound water or water of crystallisation.

Solids are usually tested using moisture balance, comprising a sensitive electronic balance equipped with an infrared heating system. Software within the balance detects when the rate of loss of mass from the sample either in absolute or percentage terms falls to a minimum value. Carbolite do not supply equipment of this type.

Where the sample material melts below the required drying temperature or where the porosity or surface characteristics of the sample result in a high level of moisture adsorption then a vacuum oven is frequenty used to dry the sample. Carbolite do not currently supply vacuum ovens.

An alternative and more labour intensive process involves heating a weighed amount of the sample material in an oven. Care should be taken that heating is not to a temperature that might loss of the sample mass through oxidation or combustion processed and that airflows in the oven chamber do not result in sample loss (or gain). Once dried the sample should be placed immediately into a dried desiccator until is re weighed to determine the loss on drying. The Carbolite AX ovens could be used for this application.

Liquids are usually tested using the Karl Fischer titration technique, however using the addition of an ‘oven’ to the Karl Fischer apparatus powders may also be tested. Carbolite do not supply Karl Fischer titrators or ovens for integration with this type of apparatus.

A wide range of techniques are employed to determine the loss on drying for gases. Carbolite do not supply products suitable for any of these techniques.