Geiger Counter meaning

A Geiger counter is a handheld Geiger–Müller detector used in legal and regulatory practice to detect ionising radiation (alpha, beta and gamma) for workplace monitoring, contamination surveys and incident response. Not defined in statute, it is a descriptive term used across health and safety, nuclear and environmental regulation in the UK and Ireland. Usage is broadly consistent across England and Wales, Scotland, Northern Ireland and Ireland. In Great Britain, dutyholders under the Ionising Radiations Regulations 2017 (IRR17) use such meters, suitably calibrated, to evidence exposure control, inform risk assessments and area designation, and verify decontamination. Equivalent duties apply in Northern Ireland (2017 regulations) and in Ireland under regulations implementing the Basic Safety Standards Directive, enforced by the Environmental Protection Agency. Typical legal use includes area and contamination surveys, emergency screening and gathering monitoring data for audits, enforcement and litigation. Key limits include: indicates count or dose rate; alpha detection needs a thin‑window probe and close proximity; not for personal dosimetry, generally poor for neutrons, and can saturate at very high fields. Maintain records of instrument specification, calibration, maintenance and user competence to satisfy regulatory expectations. Named after Hans Geiger (1882–1945).