A power electromotive force and internal resistance measurement instrument

The utility model relates to a power supply electromotive force and inner resistance measuring device which comprises a scale, a sliding block, a resistance wire, a resistance wire length selection socket, a sensitivity control key, a measuring circuit selection switch, a battery selection switch, a direct current power supply, a resistance box, a standard battery E, a tested battery E, a resistance box socket, a resistance box selection switch, a power supply switch, a digital voltage meter, a power supply adjusting knob, a digital current meter, an anode socket of the tested battery E, an anode socket of the standard battery E which are reasonably disposed on a table type device box, the sliding block is arranged on a sliding rod which is provided with two spring mental pieces, a selection switch and an output socket with scale reading line, the two spring mental pieces on the sliding block are respectively connected with the resistance wires equipped on the two sections of the scale, the sliding distance of the sliding block on the two sections of the resistance wire is displayed by the scale reading line on the two sections of the scale. The power supply electromotive force and inner resistance measuring device achieves reasonable and pretty structure, convenient operation, maintenance and collection, small measuring errors and great repeatability.