How Do Geiger Counters Work?
Definition Since you can’t see or hear radioactivity, you must use a tool like a Geiger counter to detect it. A Geiger counter is a handheld device that detects many forms of radiation. Gas and Electricity The heart of a Geiger counter is a sealed tube filled with a noble gas, such as argon or neon, mixed with a halogen, such as chlorine. Electric plates in the tube are charged with a potential of about 400 volts. When a radioactive particle passes through the tube, it conducts for a brief moment, sending a tiny current pulse through a cable coming from the tube. This is amplified and sent to an integrator, which gives a small current if the pulses are infrequent, and a larger current if the pulses are rapid. A calibrated meter displays this for the operator. Reading the Counter A control switch lets you select the meter’s sensitivity scale, so you can accurately read areas of lower or higher levels of radioactivity. The Geiger counter also has a speaker which makes a clicking sound fo
