A system for testing and documenting the electrical wiring in a building, for example, includes a Portable Circuit Analyzer (PCA) that is connected to the building's Load Center through an umbilical cord. The PCA is in wireless communication with a hand-held computer device, such as a personal digital assistant (PDA) as now widely available, provided with custom software according to the invention. The electrician connects the PCA in succession to each circuit in the building, operating each switch, and each fixture or appliance, while recording the test results of the circuit element on the PDA. The PCA measures the resistance and length of each circuit thus established. When the test process is completed, the PDA is enabled to generate a complete schematic diagram of the building, including, for example, an identification of the branch circuit to which each fixture, outlet, appliance, or other load or connection point is connected.