Developing standards to calibrate instruments used to monitor PET gas at hospitals and industrial sites.

The increase in use of Positron Emission Tomography (PET) scans, e.g. to image tumours and the human brain, has led to a subsequent increase in positron emitters and a need for primary standards to help protect patients, workers and the public from exposure to radiation. A gas counting system was used and compared with measurements from an ionisation chamber.