介绍了以西门子PLC(可编程控制器)用于薄膜测厚的全自动往复式X射线测厚仪的研制,介绍了该测厚仪的硬件构成和测厚的工作原理｡该装置已成功应用在双向拉伸聚丙烯薄膜生产线上｡ X-ray Thickness Gauge for Plastic Film JIN Qi-bing,JIANG Jing (Research Institute of Automation,Beijing University of Chemical Technology,Beijing 100029,China) Abstract:It described X-ray thickness gauge apparatus for plastic film including its working principle and hardware of its control system and the method of data processing.The equipment has been applied to BOPP product line successfully. Key words:thickness gauge;X-ray;plastic film