Transmitters are mainly used in industrial fields such as petrochemicals, metallurgy, power food, pharmaceuticals, papermaking, and textiles to detect parameters such as differential pressure, pressure, liquid level, interface, and density of liquids. When used with throttling devices, they can be used to measure flow. They convert the measured signal into 4-20MaDC and transmit it to display, calculate, regulate, or control instruments, forming various self-control systems.