The HP 4338B milliohmmeter is a precise, reliable, high-speed test tool for measurements of low resistance. Contact failure of electromechanical components in a low-current circuit is a key issue for component reliability. The HP 4338B offers selectable low ac test signals(1uA to 10mA). Users can now characterize low resistances of electromechanical components under low-current conditions. A high resolution of 10uohm allows you to determine the slightest differences in contact resistance testing of relays, switches, connectors, PC board traces and cables. The 1kHz test signal eliminates potential errors introduced by thermoelectric effects on the device-under-test(DUT) contacts. The 1kHz test signal is the best solution to evaluate the internal resistance of batteries, because it avoids dc energy consumption.