Electromagnetic flowmeter with variable-frequency conductivity-sensing function for a liquid in a tube

摘要

An electromagnetic flowmeter with variable-frequency conductivity-sensing function for a liquid in a tube includes a first microprocessor, a transducer, flow-sensing device, an exciting-current generating device, a variable-frequency conductivity measuring device, and a switch. The transducer includes coils and sensing electrodes. The switch is electrically connected to the first microprocessor and the sensing electrodes. The switch is selectively connected to the flow-sensing device or the variable-frequency conductivity measuring device according to the signals sent from the first microprocessor. The microprocessor makes the exciting-current generating device to generate an exciting current when the switch is connected to the flow-sensing device. The first microprocessor makes the exciting-current generating device stop to generate exciting current and computes conductivity of liquid when the switch is electrically connected to the variable-frequency conductivity-sensing device.

主权项

1. An electromagnetic flowmeter with variable-frequency conductivity-sensing function for a liquid in a tube comprising:
a first microprocessor; a transducer comprising two coils and two sensing electrodes; an exciting-current generating device electrically connected to the first microprocessor and the coils; a flow-sensing device electrically connected to the first microprocessor; a variable-frequency conductivity measuring device electrically connected to the first microprocessor, and a switch electrically connected to the sensing electrodes, the first microprocessor, the flow-sensing device, and the voltage-amplitude conductivity measuring device, wherein the switch makes an electrical connection between the sensing electrodes and the flow-sensing device or an electrical connection between the sensing electrodes and the variable-frequency conductivity measuring device according to a signal sent by the first microprocessor, the first microprocessor makes the exciting-current generating device generate an exciting current when the sensing electrodes and the flow-sensing device are electrically connected so as to calculate flow rate of the liquid, the first microprocessor stops the exciting-current generating device to generate the exciting current when the sensing electrodes and the variable-frequency conductivity measuring device are electrically connected, the variable-frequency conductivity measuring device outputs a square-wave signal when the sensing electrodes are immerged into the liquid so as to calculate conductivity of the liquid.