Thanks to modern logger technology continuous, high resolution data series can be recorded with a minimum of manpower. Data loggers permit the common recording, storage and management of several sensor outputs of a measurement point. In addition microprocessor-based data loggers control the measurement conditions depending on the current measured values. As a result of constant improvements in power management, the data loggers are becoming increasingly independent of mains power. The data acquisition is already completely autonomous for many applications with solar power supply and remote data transmission.