Calorimeter, in particular for heating systems

摘要

A calorimeter, in particular specified for use with heating systems, which has a temperature sensor (10) which provides an output signal which is frequency modulated in accordance with the temperature acting on it. A downstream distance discriminator (24-28) distinguishes those pulses of the temperature sensor output signal which on the basis of the temporal distance are assigned a temperature which is below the lowest normal operating temperature of the heat-dissipating body. The pulse distance discriminator consists of an AND element (24) and, upstream of one of its input terminals, a delay line (26, 28). An additional frequency generator (16, 18, 20) is used for the purpose of generating from the temperature sensor output signal a low-frequency read signal, which is then further processed in the pulse distance discriminator (24-28). A further circuit (38, 40) is provided in order to reduce the number of the pulses effectively fed from the pulse distance discriminator (24-28) to a downstream counting device (42), and this permits the bead frequency to be located at a value greater than zero in the case of room temperature. A temperature sensor (84) for use in such a calorimeter has a liquid-filled pressure cell (94, 100) which has a metallic diaphragm (100) and a metallic plate (96) opposite the latter. Said plate can be thermally coupled to the heat-dissipating body, and forms together with the diaphragm (100) a condenser of variable capacity which is connected as a frequency-determining component to a resonant circuit. <IMAGE>