Radiation measurement is a fundamental aspect of environmental chemistry, especially in monitoring radioactive contamination, assessing occupational exposure, and studying environmental radioactivity. Various instruments are employed to detect, quantify, and analyze ionizing radiation, which includes alpha particles, beta particles, gamma rays, and neutrons. Each type of radiation requires specific detection techniques due to differences in penetration ability, energy, and ionization properties. One of the most commonly used instruments is the Geiger-Müller (GM) counter. It consists of a gas-filled tube with an electrode system; when radiation passes through, it ionizes the gas and produces an electrical pulse. The GM counter is highly sensitive to beta and gamma radiation and provides rapid detection. However, it does not provide detailed energy information or discriminate between different types of radiation efficiently. It is widely used in environmental monitoring to quickly assess radiation levels in soil, water, and air. Another key instrument is the scintillation detector, which uses materials such as sodium iodide (NaI) doped with thallium. When ionizing radiation strikes the scintillator, it emits flashes of light that are converted to electrical signals by a photomultiplier tube. Scintillation detectors can detect alpha, beta, and gamma radiation and are valued for their high sensitivity and capability to measure radiation energy, which allows for isotope identification. They are particularly useful in monitoring radioactive fallout, environmental contamination, and tracking radionuclide migration. Ionization chambers are gas-filled devices that measure the total charge produced by ionization in the chamber.