In all ecological studies, knowing the physicochemical conditions of specific locations is as important as knowing what species occur and how extensive their populations are. Abiotic parameters are measured with devices, and the measured values can now be recorded continuously using data loggers. Modern devices can measure and record many parameters simultaneously. We also present devices and techniques that can be used to collect data if no electricity is available. Ecologically, sums of parameter values, such as temperature sums and sunshine duration, are often more significant. Detailed instructions for precise measurements are provided.