Radiation contamination monitor probe. Probe used to send radiation contamination and dose rate readings to a survey meter. Contamination monitors measure the level of contamination present on an object that has been exposed to ionizing radiation. Dosimeters (dose rate meters) measure exposure to ionizing radiation. They are often used by people who are exposed to radiation regularly during their work. There are strict limits to the amount of radiation to which nuclear industry workers, and those working with radioactive materials in laboratories, can be exposed. Devices such as these help ensure the workers' exposure is kept within these limits.