α测厚仪用于任何材料的超薄膜厚度测量，范围0~4mg/cm

2

，精密度好于1.5%。由于采用了空气等效法，使测量过程能在空气中进行。仪器简单、精密度高。本文推导了相对质量阻止本领作为

E

α

、

Z

和

A

的函数的半经验公式，它和齐格勒数据表的偏差小于8%。

An α-ray thickness gauge has been designed for the purpose of thickness measuring of ultra-thin °foils (0~4mg/cm

2

) made of any material. The precision is better than 1.5%. By using air equivalent method

it is possible to measure samples in the air to simplify the instruments used and to obtain higher precision. A semi-empirical formula for the relative mass stopping power as a function of E

α

Z and A has been derived. The divergency between the results from the formula and the data from Ziegler's table is less than 8%.