High resolution ac calorimeter for organic liquids.

ABSTRACT

A calorimeter has been developed for organic liquids which utilizes the ac heat capacity technique. It can measure heat capacity changes of 1 part in 10(4) with a temperature resolution better than 1 mK from room temperature to 200 degrees C. This calorimeter has been used to study the smectic A to nematic phase transition in a series of homologous liquid crystals.