We discuss the asymmetric double Langmuir probe (ADLP) and demonstrate the possibility of using it to measure plasma temperatureTeand densitynwhen it is operated in the region of small signal response. The area of one of the ADLP collectors is considerably larger than the other. This probe can be operated at a relatively low applied voltageeVa/Te<1, and still provides sufficient information to determine the plasmaTeandn. There is no need for a direct measurement of the ion saturation current, which can be on the order of a few amperes in large fusion devices. This reduces the requirements on the probe power supply.