Optical density meter for X-ray images

Described is the design of simpe and compact device which determines the optical density of X-ray images with the error not more than +-3%. A photoresistor with high thermostability is used in the device as a converter. A base diode carries out a function of logarithmation. Justified is the linearity of the electric conversion tract characteristic, presented are the principle scheme of the device and the comparison of its specifications with RDA 81 densitometer of the ''Sacura'' firm (Japan). The meter described is destined for application in semistationary laboratories equipped with the means of radiography permitting to perform non-destructively quality testing of ring welded joints of pipe-lines under track conditions