The mechanical contact relays of the AM16/32B are subject to corrosion and pitting, which leads to increased relay resistance and greater variations of the resistance with each contact cycle. Switched currents in excess of 30 mA degrade the relay contacts involved, rendering the channel unsuitable for further low-level analog measurements. (If an AM16/32 relay has been used for currents greater than 30 mA, it is not suitable for low-level mV measurements.) The switching of higher level currents causes increased corrosion and pitting of the relays. The solid-state relays on the AM25T multiplexer are not subject to corrosion and pitting; therefore, they are more suitable for low-level mV signals.