TWO-ELECTRODE IONIZATION CHAMBER OF X-RAY EXPOSURE METER Russian patent published in 1999 - IPC

FIELD: industrial X-ray filming, in particular, ionization chambers for producing X-ray films with given exposition density. SUBSTANCE: ionization chamber of X-ray exposition meter with air filling is located behind X-ray film under exposition and contains collecting electrode, high-voltage electrode and protection electrode. Electrode of ionization chamber which is first with respect to X-ray beam direction is made from material, which is transparent for X-rays, and is covered with metal coating of copper, zinc or nickel of 1.4 mg per sq. sm. Air gap between two electrodes is within range of 6-10 mm. Second electrode is made from material with high nuclear weight, for example, lead or bismuth with depth of at least 60 mcm. In addition device housing is made from metal and serves as protection electrode. EFFECT: possibility of on-line ionization chamber hardness matching for X- ray film, when ionization chamber is located behind film under exposition. 2 cl, 1 dwg