The small flow small-diameter corrosion-resistant flowmeter has a fluid density setting and can display mass flow rate; Using non-volatile memory with *, the circuit has higher reliability and effectively protects settings and measurement parameters; Frequency programmable low-frequency three value wave excitation improves the stability of flow measurement zero point and has low power loss. It is used to measure the volumetric flow rate of conductive liquids and slurry liquids in closed pipelines, and is suitable for industries such as petrochemicals, steel metallurgy, water supply and drainage, water conservancy irrigation, water treatment, environmental wastewater total control, power, papermaking, food, etc. It can be controlled by a computer to achieve system control.