do radon fans have to run continuously

http://business.bentoncourier.com/bentoncourier/news/read/39927116/What_are_the_Symptoms_of_Radon_Poisoning?

Long-term tests call for a device that continues to be in the residence for longer than 90 days at once. Radon professionals can execute both kinds of examinations in your house, but more than likely will run several