Convective air flow dynamic calorimeter

A convective air flow dynamic calorimeter, for measuring the heat emission of a burning sample, comprising:

• a. a combustion chamber extending vertically for holding therein a sample to be tested for burning characteristics thereof, said chamber including door access means to facilitate placement and removal of samples;
• b. an air inlet opening positioned at the external ambient environment;
• c. an air inlet duct extending to said combustion chamber from said air inlet opening to provide a supply of ambient air to said combustion chamber;
• d. an elbow duct means connecting said air inlet duct to said combustion chamber;
• e. air outlet means extending from said combustion chamber to provide a path of exhaust therefrom;
• f. air flow restriction means in said air inlet duct to minimize extraneous air currents therethrough;
• g. a first thermistor to act as an anemometer sensing means positioned between said air inlet opening and the test sample in said combustion chamber to sense the air flow therethrough;
• h. a second thermistor positioned in the external ambient environment;
• and
• i. an electrical bridge circuit means for comparing the resistance values of said first thermistor and said second thermistor to indicate the flow of air through the calorimeter said flowrate being a measure of the heat emission of the burning sample.