초록 ▼

An apparatus for measuring a flow rate of a powder when a powder is conveyed by using air as a carrier gas, which apparatus measures the flow rate based on the change of capacitance of the powder to be measured. The apparatus that can measure the flow rate of a powder with high accuracy by compensat

An apparatus for measuring a flow rate of a powder when a powder is conveyed by using air as a carrier gas, which apparatus measures the flow rate based on the change of capacitance of the powder to be measured. The apparatus that can measure the flow rate of a powder with high accuracy by compensating for the effect of the thermal drift of the capacitance. It includes a protecting pipe for conveying a powder, a housing pipe having measuring electrodes, and a transducer for outputting an output of the measuring electrode to a display. It further includes an atmospheric temperature sensor and a carrier gas-temperature sensor 31. The sensor 31 is directly fixed to the protecting pipe 20 at a place that does not overlap the housing pipe 10, and includes a circuit for compensating for the output of the measuring electrode, which output is the capacitance determined based on a graph of a curve of the relationship between a capacitance and a flow rate, based on the difference between the output of the atmospheric temperature sensor and the output of the carrier-gas-temperature sensor.

대표청구항 ▼

What we claim is: 1. 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, whic

What we claim is: 1. 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, anda 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, andwherein 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.