Interactions between electromagnetic radiation, charged particles and atoms of matter that provide the basis for detection. Ionization, recombination, atomic excitation processes. Detector efficiency, energy resolution, dead time, escape and pile-up phenomenon, response function. Gas ionization detectors: ionization chamber, proportional counter, Geiger-Müller detectors, drift detectors. Scintillation detectors, LSC detector technology. Operating principle of semiconductor detectors: HPGe, Si(Li), PIN diode, SDD and superconducting detectors, their structure and applications. Special detector types and detection techniques: Cherenkov counter, radiography, solid-state trace detector, termoluminescent detector, cloud- and diffusion chamber. Estimation of the uncertainty of nuclear measurement results: probabilistic properties of X-ray, gamma and alpha spectra, error calculation, mathematical description of spectra, detection limit of analytical methods. Basics of spectroscopy, detector types for different spectroscopic applications. Measuring instruments of alpha, X-ray and gamma spectrometry, structure of nuclear spectrometers. Basic instruments of electronic signal processing and their characteristic technical properties, analogue-digital conversion. Particle accelerators and their applications. Methods for quantitative evaluation of gamma and X-ray spectra. Neutron detection, major neutron detectors and their applications. Special nuclear measurement methods: measurement of small and large activities, background reduction methods. Quality assurance of the nuclear measurement laboratory. Dosimetry detectors.