Radiation measurement is an integral part of environmental chemistry since radioactive isotopes and radiation sources are present both naturally and through anthropogenic activities. The measurement of radiation requires specialized instruments that can detect and quantify the type, intensity, and energy of radiation. These instruments form the backbone of radiochemical techniques that are further applied in environmental monitoring to assess contamination levels, trace radionuclide behavior, and evaluate the impact of radioactive pollutants on ecosystems. Understanding the working principles and applications of these instruments provides clarity on their relevance in environmental studies. The most common instruments used for radiation measurement include Geiger-Müller counters, scintillation counters, semiconductor detectors, ionization chambers, proportional counters, and neutron detectors. Each of these has unique characteristics depending on the type of radiation to be measured, its energy range, and the required precision. The Geiger-Müller counter is one of the most widely used instruments for general radiation detection. It consists of a Geiger-Müller tube filled with a gas mixture, where the passage of an ionizing particle creates a cascade of ionizations, producing a measurable pulse. The device is effective for detecting alpha, beta, and gamma radiations but has limitations in energy discrimination. In environmental monitoring, it is used for quick surveys to detect radioactive contamination on surfaces, soil, or in atmospheric particles. Scintillation counters provide higher sensitivity and energy resolution compared to Geiger-Müller counters. They use scintillating materials like sodium iodide doped with thallium (NaI(Tl)) or plastic scintillators, which emit photons when struck by radiation. The emitted light is then converted into an electrical signal by a photomultiplier tube. Scintillation detectors are particularly useful in environmental analysis for gamma spectroscopy, where they can identify specific radionuclides based on their energy signatures. This makes them essential in tracing radioactive contamination in water bodies, soil, and vegetation. Semiconductor detectors, such as high-purity germanium detectors, are widely recognized for their superior resolution in gamma-ray spectroscopy. These detectors operate by generating electron-hole pairs when radiation interacts with the semiconductor material, and the resulting current is measured. Due to their high precision, they are used in laboratory analysis of environmental samples where identification of radionuclides with very close energy levels is required. For instance, in monitoring fallout from nuclear accidents, semiconductor detectors provide detailed insight into isotopic compositions