An electrode tool for electrochemical machining includes a machining electrode surface. A set of pre-generated sparse projection vectors is obtained. A host processor can provide the libraries and a list of objects to and delivered to the onboard mobile processor. The invention utilizes a unique method of spectrographically measuring the hydrofluoric acid when in contact with added chromogenic agents to obtain exact measurements that are accurate, immediate, and safe. The at least one third terminal is for the detection of shorting.