Once again I am seeking participants for a radon-in-water intercomparison. No radioactive materials license is necessary. Participants are welcome to keep the reusable standard for their future use. There is no Ra-226 added to the water, as the source is sealed and of an exempt quantity.
I have attached a picture of the bottle that participants will receive. The participants will determine the radon content of the water using their method and send me the result. International laboratories are invited to participate. This exercise is meant to examine the participants ability to quantitatively transfer and measure radon in a water sample, as well as apply a proper decay correction.