This study evaluates the performance characteristics of three different torches. A variety of different sensor systems were used to determine how each system resolves the differences in torch spray conditions. Torch performance characteristics include the long term drift behavior in terms of spray pattern and coating profile, the ability to control the particle state, and each torches nonlinear characteristics such as bifurcation (sudden jumps) and on/off repeatability. Sensors include commercially available particle sensors (Tecnar’s DPV 2000, Oseir’s Spraywatch, and Inflight’s IPM), as well as monitoring of plume intensity, acoustic emission, and high frequency voltage/current. Torches include Praxair’s SG 100 (internal injection), Sulzer Metco’s 9MB, and Progressive Technologies 100 HE. The study focused on spraying YSZ under each torches typical operating conditions. Abstract only; no full-text paper available.