Abstract Abstract An isoperibolic calorimetric cell, formed with double plastic insulation, is connected to a conventional Dewar glass. The cell has a lid on which are placed an electronic thermometer and an electric resistor to provide the cell with specific quantities of electrical work. The thermometer, built with an LM35 integrator circuit, presents an output potential signal which is proportional to the temperature and close to its direct reading. This makes it easy to use the way a conventional precise mercury thermometer is used. Calibration curves of the IC thermometer and of stabilization appear, which show good insulation for the system. Additionally, the thermometer potential response for electric heating within the cell is shown through an electrical resistor in a range from 576 to 54 J. The response time of the IC thermometer is shown with mixtures of water at different temperatures, and also with NaOH and HCl solutions. Keywords: Isoperibolic calorimetryTemperature ICTemperature measurementThermometric sensitivity ACKNOWLEDGMENTS The authors thank the Departments of Chemistry of Universidad Nacional de Colombia and Universidad de Los Andes and the Agreement established between these two institutions.