The Metrohm 743 Rancimat is a computer-controlled instrument for oxidative stability analysis of fats, oils and other rendered products, including biodiesel.
The 743 Rancimat has eight sample positions, two separate heating blocks and software for controlling methods, samples and data.
Air is blown through the heated and thermostatted sample (50-220C) in order to oxidise it.
The stream of air then carries over the volatile oxidation products (normally formed at the end of the oxidation process) to a measuring vessel containing de-ionised water.
The readings of the conductivity measurement can be plotted as a function of the time required for the oxidation.
The inflection point of this oxidation curve is known as the induction time, which serves as a measure of quality of the oil tested.
The temperature of heating each block in the 743 Rancimat, containing four disposable sample vessels, can be controlled separately.
This setup allows the analysis of several different oils simultaneously.
The 743 Rancimat also allows shelf-life prediction of natural oils and fats.