BATTERY INTERNAL IMPEDANCE METER.

Recently battery-internal resistance has become an important item of battery characteristics when designing power sources for electronic equipment. Strict quality control of batteries has therefore become necessary. A portable measuring instrument which can be used to measure battery-internal resistance easily and to obtain a reproducible measured value is needed. This paper presents a direct-reading internal-resistance meter operated by batteries. In addition, a special probe which can be used to measure low resistance accurately by the four-terminal method is described.