The Principle of Operation
Thermal weed control method is based on the destruction of plant cells by boiling cell water to such an extent as to break the cell's ability to carry out photosynthesis. We don't need to charr the cell. The plant must be exposed to flame just a split second until the water evaporates in the cell.
This can be checked by squeezing the plant with fingers and if the plant shows fingerprint, the goal has been reached and the cells are destroyed. It is important that the plant is greater than weeds or grass, which we repress. The smaller the weeds, the more effective the method.