The spherical graphite chambers PS-50 and PS-10 are vented ionizing chambers for use as primary standard for radiation protection measurements and absolute dosimetry. They have been designed in collaboration with the Radiation Interactions and Dosimetry Group at the National Institute of Standards and Technology (NIST).
The exact volume of each chamber is determined individually. The homogeneity of the walls and electrodes is 0.06 mm.
The chambers are constructed with a long rigid stem of approx. 29 cm length for easy mounting in the radiation beam. Air density correction is required for each measurement.