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

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.