The R&S®NRP18S-10, R&S®NRP18S-20 and R&S®NRP18S-25 high-power sensors consist of an R&S®NRP18S and an attenuator and are able to perform power measurements up to 2 W, 15 W and 30 W. When used with the attenuator, mismatch errors between the sensor and attenuator are automatically corrected. The S-parameters for the attenuator are determined and stored in the sensor during production. They are then automatically taken into account when performing measurements.