Ardran G M, Crooks H E
Br J Radiol. 1978 Jan;51(601):29-34. doi: 10.1259/0007-1285-51-601-29.
The penetrameter cassette, when used with suitable filters and calibrated against the same average wave form, can detect changes of less than 1 kV in the range 20-50 kV, 1 kV from 50-100 and from 1-4 Kv from 100-400 kV. Problems of calibration are discussed together with the necessity to use a suitable shutter with equipment which has a significant build-up and decay time during which the radiation quality may be varying. Extra-focal radiation does not normally present a significant problem in the measurement of kV, but when the penetrameter is used to measure inherent or total filtration extra-focal radiation can be a problem and may be similar in degree to the effects of varying target angles. When used to determine filtration, the generator used for calibration of the penetrameter and the one being measured should be adjusted to have the same target angle and similar degrees of extra-focal radiation by altering the size of the tube aperture as close to the focal spot as practicable. The results presented confirm the accuracy and convenience of the penetrameter for the measurement of kV and filtration over the extended range of energies.
穿透计暗盒与合适的滤过器一起使用，并针对相同的平均波形进行校准，在20 - 50 kV范围内可检测到小于1 kV的变化，在50 - 100 kV范围内可检测到1 kV的变化，在100 - 400 kV范围内可检测到1 - 4 kV的变化。讨论了校准问题以及在使用具有显著累积和衰减时间（在此期间辐射质量可能会变化）的设备时使用合适快门的必要性。在千伏测量中，焦点外辐射通常不会造成重大问题，但当穿透计用于测量固有滤过或总滤过时，焦点外辐射可能会成为一个问题，其程度可能与不同靶角的影响相似。在用于确定滤过时，用于校准穿透计的发生器和被测量的发生器应进行调整，通过在尽可能靠近焦点的位置改变管孔径大小，使它们具有相同的靶角和相似程度的焦点外辐射。给出的结果证实了穿透计在扩展能量范围内测量千伏和滤过的准确性和便利性。
