This chapter provides a comprehensive overview of the detectors routinely employed in particle therapy (PT) clinics, with a particular emphasis on proton and carbon-ion modalities. We explored detectors commonly used for PT: scintillation detectors, Faraday cups, microdosimeters, the Zebra multilayer ionization chamber, and the Wendi-II neutron detector. We included details of their operating principles, clinical implementations, and operational limitations. Some conventional dosimeters, such as ionization chambers and radiochromic film, which were commonly used for measurements of conventional radiotherapy, have gained renewed importance in particle beams with new developments, such as the Bragg peak chamber, due to special clinical needs. Here, we highlight their specialized applications and constraints in the context of charged-particle dosimetry to avoid redundancy with earlier chapters. The chapter then surveys emerging technologies, including strip-ionization-chamber arrays (SICA), three-dimensional (3D) detectors, and Cherenkov measurements, and discusses their potential to advance treatment verification and research. Finally, we address critical safety and measurement challenges posed by detector activation and the ultra-high dose rates characteristic of FLASH therapy, focusing on issues of temporal resolution, accurate dose rate quantification, and monitor-chamber saturation. Together, these sections offer a practical guide for clinical physicists and a roadmap for future innovation in PT dosimetry.