1. A performance arc time measurement apparatus comprising: a) a control circuit comprising a processor, a RAM, and EPROM, and ACIA, an RS232 Serial Data Port, and a clock; b) an arc time sensor circuit electrically connected to the first circuit, the arc time sensor circuit comprising an analog to digital converter, one or more control buttons, a power switch, and a human-readable display, a battery charger circuit, and a sensor input circuits; c) an arc time measuring means electrically connected to said arc time sensor; and d) an electrically conducting wire or cable connected at one end to the arc time measuring means, and having a second end adapted to connect electronically to a power source of a welding device.