The Industry Leader and your Partner in Smoke Testing over 60 years – Superior Signal Company offers both Classic Smoke Candles and Smoke Fluid Systems, plus Air/Smoke Blowers engineered for all your Smoke Testing needs. The Superior Smoke Testing Technique remains the Industry Standard for Sewer Smoke Testing, and the most cost effective method to find sources of Surface Inflow. Classic Smoke Candles provide the most visible smoke so you can find more faults, and at a longer distance. Superior Smoke Fluid Systems use a proprietary insulated heating chamber with stainless steel injector to maximize dry smoke output, and produce the best quality liquid-based smoke. Other smokes are not Superior.