Replacing Mechanized Oxyfuel Cutting Sensors With Ion Current Sensing

This paper describes a method using electrical characteristics of the torch, flame, and work piece to replace active sensing elements most commonly used for mechanized oxyfuel cutting applications; height, fuel/oxygen ratio, work temperature, and preheat flow rate. Calibrations are given for the torch under test for standoff accurate to ±1/32 in (0.8 mm) and F/O ratio accurate to ±.008. Methods are proposed for balancing flow across multi-torch systems, and detecting the work kindling temperature. Additional work is needed if calibrated flow and work temperatures are to be measured electrically.