Design of molten steel liquid level detecting system based on eddy current testing

In order to measure the molten steel level in the mold, a set of molten steel liquid level detecting device was designed based on eddy current method. Firstly, the eddy current sensor for measuring the liquid level of molten steel was designed by using the electromagnetic simulation of ANSOFT Maxwell 3D software. Then, based on the PIC micro controller, the hardware circuit and the software program of the liquid level detecting device were designed. The liquid level of the molten steel was displayed on the HMI touch screen, and the 4–20mA signal was output. At last, the measurement results of different magnetic permeability materials were analyzed, and the measurement accuracy was improved greatly by using multi-segment linear interpolation method in the program. The molten steel liquid level detection system has been applied in practice. The results show that the system has high precision, high reliability and can replace radioactive isotope detection method. It has good market application prospect in future.