Direct read metering device and direct read water meter

摘要

The present invention discloses a direct read metering device, comprising a digital counting wheel connected with a rotary shaft, a micro-controller—a ring magnet coaxially installed on the digital counting wheel, and a tunneling magnetoresistive angular displacement sensor installed radially displaced from the central axis of the annular magnet; the tunneling magneto-resistive angular displacement sensor and the ring magnet are separated by a certain distance in the direction parallel to the central axis of the ring magnet; the micro-controller is connected to the tunneling magnetoresistive angular displacement sensor and used to convert the output of the tunneling magnetoresistive angular displacement sensor into a readable number. The device uses the tunneling magneto-resistive angular displacement sensor to sense the angle of a rotary magnetic field generated by the rotation of the ring magnet which is installed on the digital counting wheel in order to permit the code of the digital counting wheel to be determined when the meter is read, thus realizing a direct read metering function. This direct read metering function is applied to provide a direct read water meter.