Patent ID: 8061217

Claim:
An apparatus that uses capacitance for measuring a flow rate of a powder and that comprises: a measuring pipe, through which a powder together with a carrier gas pass, for measuring a flow rate, a measuring electrode for measuring changes of capacitance in the measuring pipe, which electrode is disposed around the measuring pipe, a circuit (“a transducer”) for transducing the capacitance, for outputting an output of the measuring electrode to a display for displaying a flow rate of a powder, wherein the measuring electrode and the transducer are hermetically housed in a casing and are held together with the measuring pipe, an atmospheric temperature sensor for measuring the temperature of the atmosphere and a carrier-gas-temperature sensor for measuring the temperature of the carrier gas, and a circuit for compensating for the output of the measuring electrode based on the difference between the output of the atmospheric temperature sensor and the output of the carrier-gas-temperature sensor, wherein the carrier-gas-temperature sensor is disposed on the measuring pipe at a place that is not affected by the measuring electrode, and that is near the inner wall of the measuring pipe, and wherein the atmospheric temperature sensor is disposed so that the sensor can measure the temperature of the atmosphere surrounding the apparatus for measuring a flow rate of a powder.