Blendl C, Buhr E
University of Applied Sciences, Cologne, Germany.
Med Phys. 2001 Dec;28(12):2420-6. doi: 10.1118/1.1418723.
The effects of different film processing conditions on light and x-ray sensitometric responses were compared for a variety of double-emulsion x-ray films. The processing conditions were altered by changes of the developer temperature. Three different exposure variants were applied: x-ray sensitometry using two stepped neutral density attenuators between film and screens, simultaneous double-sided light sensitometry, and single-sided light sensitometry. 13 different types of double-emulsion x-ray films were investigated, among them three asymmetric films. In the special case of exposing the asymmetric films with the single-sided light sensitometer, a method was investigated where each side of the film is exposed at different locations and the sum effect is analyzed. From each sensitometric curve shape two parameters, the logarithmic speed (logS) and the average gradient (G), were evaluated. The results of this study can be summarized as follows: (1) Single-sided and double-sided light sensitometers revealed almost equal changes of logS when the processing conditions are altered. Thus, single-sided light sensitometers can serve as a substitute for double-sided light sensitometers provided that suited exposure methods are used and appropriate sensitometric parameters are evaluated. (2) Light sensitometry quantitatively indicated changes of the film processing that affect the x-ray speed. Hence, light sensitometry is a useful method to monitor changes in film processing.
针对多种双乳剂X射线胶片，比较了不同冲洗条件对光和X射线感光度响应的影响。通过改变显影液温度来改变冲洗条件。应用了三种不同的曝光变体：在胶片和增感屏之间使用两个阶梯式中性密度衰减器的X射线感光度测定、同步双面光感光度测定和单面光感光度测定。研究了13种不同类型的双乳剂X射线胶片，其中包括三种不对称胶片。在使用单面光感光度测定仪对不对称胶片进行曝光的特殊情况下，研究了一种方法，即胶片的每一面在不同位置进行曝光，并分析其总和效应。从每条感光度曲线形状中评估两个参数，即对数感光度（logS）和平均梯度（G）。本研究结果可总结如下：（1）当冲洗条件改变时，单面和双面光感光度测定仪显示出logS的变化几乎相等。因此，只要使用合适的曝光方法并评估适当的感光度参数，单面光感光度测定仪可替代双面光感光度测定仪。（2）光感光度测定定量地表明了影响X射线感光度的胶片冲洗变化。因此，光感光度测定是监测胶片冲洗变化的一种有用方法。
