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DGX型软X射线机是一种探测乳房肿瘤分辨率较高的医用设备,同时它也可作集成电路质量、种子成活率和病虫害检查用。生物学上不仅用它拍摄标本,且作为辐射源研究软X线的生物效应。在实际使用中我们发现该设备有两个不足之处,曝光时间不够长(0-9.9秒)和计时不够准确。前者,现在使用冷却水回流使x线管散热的办法,得到了较好地解决。后者,为了改进时间控制的精度,采用石英晶体振荡,PMOS集成元件分频计时,用逻辑电路进行全机工作状态的控制。由于石英晶体振荡器的频率稳定度很高,因此经改进后的计时十分正确,工作稳定可靠。同时,我们还将时间选择范围从0-9.9秒扩展到0～999.9秒,并有预选曝光时间、中断曝光和累加等项功能,这样就满足了多
The DGX soft X-ray machine is a medical device with high resolution for detecting breast tumors. It can also be used for IC quality, seed survival rate and pest inspection. Biology not only use it to take specimens, and as a radiation source to study the biological effects of soft X rays. In actual use, we found that the device has two shortcomings, the exposure time is not long enough (0-9.9 seconds) and the timing is not accurate enough. The former, the use of cooling water back to the x-ray tube cooling method, has been better resolved. The latter, in order to improve the accuracy of time control, the use of quartz crystal oscillation, PMOS integrated components frequency timing, with the logic circuit for the whole state control. Due to the high frequency stability of the quartz crystal oscillator, the improved timing is quite correct and the work is stable and reliable. At the same time, we also extend the time range from 0-9.9 seconds to 0-999.9 seconds, with pre-selected exposure time, interrupt exposure and accumulation, etc.