After the molten glass in the furnace is shut down and emptied, to verify the active form of the molten glass can also judge the general situation of the molten glass in the operation process by observing the washing traces of the molten glass on the bottom of the glass furnace and the refractory on the tank wall, which provides a basis for analyzing and formulating the further improvement direction of the furnace.

The trajectory of glass liquid particles in actual glass kiln construction can be determined by isotope tracing method. Firstly, isotope particles are put into the batch, and detection devices are arranged near the furnace to locate the movement process of isotope particles and track the movement track of isotope particles. This method has high technical requirements and difficult implementation, and is rarely used in practical engineering. Another method is contrast method, in which contrast agent is added by pulse method during feeding. One side of the glass kiln wall is equipped with a gamma-ray emitting device, and the other side is equipped with a synchronous receiving device, and both sides scan the glass melt of the glass furnace synchronously. Because the contrast element has strong ability to absorb gamma rays, two-dimensional electronic images of the furnace can be obtained, and the dynamic concentration distribution information of refueling in the glass melt can be obtained through image analysis.

In actual operation, the temperature of designated points in the furnace can be measured by optical pyrometer through observation holes in different parts, and the information of glass melting conditions in large-scale float glass furnace can be obtained indirectly. This method can sometimes achieve good results.