Flow rate measuring apparatus

摘要

The invention is a new and novel flow rate measuring appartus comprising constant voltage or constant power anemometers with unique electronic circuits for maintaining constant voltage or constant power to a hot film or hot wire sensor. The constant power or constant voltage mode of operation is achieved by providing an operational amplifier with a negative feedback circuit driving the hot element sensor. The hot element sensor is located along the negative feedback path of the circuit between a first and second impedance. Amplifying and filtering circuits are also provided.