Radon ²²² is a radioactive noble gas that is formed in the decay of the primordial 238U decay chain, with an average abundance of 3 parts per million (3 g ⋅ t-1) in the earth's crust. Since radon is the only noble gas in the decay chain, it has with its half live T12 = 3.8232(8) d, the ability to emanate from the ground or building materials and to interfere with the biosphere. Taking into account Directive 2013/59/Euratom, the EURAMET EPM project RadonNET was founded to find a trade-off between energy efficiency and health effects by means of measurements with small uncertainties. With this in mind, an pulse ionization chamber for the time-resolved measurement of radon activity at low concentrations is described here. The solution shown is characterized by low sensitivity to room and impact noise. Experimental investigations show the properties of the pulse ionization chamber under various conditions, particularly with regard to its use in sensor networks in larger buildings or future cities.