The image resolution of the 9 inch image intensifier is that under the irradiation of 45 kV X-ray tube voltage and 0.1 mA current, a resolution test card composed of appropriately arranged heavy metal wires without X-ray transmission and their gaps is placed in front of the input screen of the 9 inch image intensifier. The logarithm of black and white lines can be seen clearly in the output image within 1 cm width. The line measured in this way is called the resolution of the image. At present, the resolution of the 9 inch image intensifier can reach 25~50 lines above /cm.
The higher the image resolution of the 9 inch image intensifier, the better the image effect, the clearer the picture of the physical examination, is conducive to the diagnosis of the disease.