This sensor, called the Z-Scan, was originally produced by Advanced Energy. Wallace Design was given the task of reverse engineering and subsequently producing it. In addition to the original configuration, Wallace Design engineered and produces a 50ohm impedance-compensated unit, an ultra-high-voltage unit, and has procured a wide variety of bespoke units for direct integration into existing equipment. Unlike the original units, all of these sensors can be rebuilt in the field. The sensors typically benchmark at around triple the accuracy of the original sensors. These sensors, as well as robust support and training, can be purchased from FTS Plasma in Fort Collins.