Dixon R L, Ekstrand K E
Med Phys. 1979 Sep-Oct;6(5):436-40. doi: 10.1118/1.594533.
A calibration monitor has been designed for measuring the constancy of linear accelerator or cobalt unit output between full calibrations. This monitor is battery operated, light-weight and slides into the shadow tray attachment on a linear accelerator or cobalt unit for easy setup. It provides a digital readout of the dose delivered, and a consistency check can be made in less than two minutes. The precision of the monitor, determined by cobalt-60 irradiations over a 2 1/2 period, is +/- 0.6% (standard deviation). The monitor also retains the dose reading in a CMOS digital counter indefinitely, hence it can be used in the same fashion as mailed thermoluminescent dosimeters (TLD) for calibration checks at remote facilities without the complicated readout procedures associated with TLD. The monitor can be mailed to a remote facility, positioned without ambiguity, and irradiated; and the reading can be verified on return to the originating center simply by pressing a switch. The monitor can easily be set up to carry out a "blind" check in which the reading obtained is not known to the remote facility.
已设计出一种校准监测器，用于测量直线加速器或钴治疗机在两次完全校准之间输出的稳定性。该监测器由电池供电，重量轻，可滑入直线加速器或钴治疗机的阴影托盘附件中，便于安装。它能提供所输送剂量的数字读数，并且在不到两分钟的时间内即可进行一致性检查。通过在2个半月的时间内用钴-60进行照射确定，该监测器的精度为±0.6%（标准差）。该监测器还能将剂量读数无限期地保存在CMOS数字计数器中，因此它可像邮寄热释光剂量计（TLD）一样用于远程设施的校准检查，而无需TLD相关的复杂读出程序。可将该监测器邮寄到远程设施，准确放置并进行照射；返回原中心后，只需按下一个开关即可验证读数。该监测器可轻松设置以进行“盲”检查，即远程设施不知道所获得的读数。
