胶片生产过程中有许多环节需要计量片基长度。以往用的机械电动计数器,每台278元,字码太小,暗室不易分辨;若用电子数字计数器,每台价2000元左右。而且选择采样辊筒也很麻烦:若选主动辊,位置和直径不一定合适;而选被动辊,需带动一套变速(变径)装置又容易丢转。使用计算器则可弥补这两方面的不足。现以EL-8131型计算器为例:找一根合适的辊筒,如涂布辊,设 There are many aspects of the film production process need to measure the film base length. Previous mechanical electric counter, each 278 yuan, the code is too small, darkroom is not easy to distinguish; if the electronic digital counter, each price of about 2,000 yuan. And the choice of sampling roller is also very troublesome: If you choose the driving roller, the position and diameter may not be suitable; and choose the passive roller, you need to drive a variable speed (diameter) device and easy to lose. Using a calculator can make up for these two shortcomings. Take EL-8131 type calculator as an example: Find a suitable roller, such as coating roller, set