Soil scientists work with many types of technology, from extremely simple (hands, picks, and water bottles) to extremely complex. Some of the advanced technologies include: geographic positioning systems, geographic information systems, laser surveying systems, infrared thermometry, multispectral imagery, X-ray spectroscopy (mineralogists), several types of spectrophotometers (atomic absorption, plasma emission, etc.; fertility and environmental specialists), respirometers (biologists studying the activity of soil organisms), time domain reflectometry and various types of psychrometry