The U.S. Secret Service estimates that some $1 billion of counterfeit U.S. dollars are printed every year. Ninety percent of that amount is confiscated by authorities before distribu- tion, but that still leaves $ 100 million floating around the world at any one time. People worry about getting stuck with funny money, and some buy devices that can help them determine whether a bill is counterfeit. The most common type of detector uses ultraviolet light to spot a bill that has been bleached and then reprinted ----a recent counterfeiting technique.
Now comes a new device for discovering bogus bucks that is more convenient than competing products , and as effective. It is called the Vistatector. Every major currency in the world, except French francs and West German marks printed before 1973, has magnetic particles embedded on the face of the bill. The particles （which enable counting machines to process stacks of money） are present in the printing ink and lie on certain predetermined spots on individual bills. The Vistatector is a penlike device that uses electronic circuit to detect whether the magnetic particles are present on a bill -- and if so, if they are located where they should be. 现在出现了一种新的探测假币的装置，这种装置比与之竞争的其他产品更为方便，且同样有效。它就是展测仪。世界上的各种主要货币，除了法郎和1973年之前印刷的西德马克外，在纸币的表面嵌有磁粉。这些粒子（粉末）（能使计数机对大量的钱进行分理）存在于油墨中，并在各张纸币的预定点显现。展测仪是一种钢笔形状的仪器，用电子线路查出纸币上是否存在磁粉——如果纸币上是有磁粉的，那么还要看它们是否在准确的部位。
Users rub the bottom of the “pen” back and forth across two different spots on a bill, and indicator lights signify whether magnetic particles are embedded in those areas. If the bill is genuine, the product will show the presence of particles in one spot and the absence of them in the other. Unlike ultraviolet detectors that require the user to make subjective color comparisons to determine the authenticity of a bill, the Vistatector requires no human decision making. 使用者用“笔”的底部在纸币上的不同点来回擦拭，指示器的光线显示所经部位是否嵌有磁粉。如果纸币是真的，该产品就会显示有的部位有磁粉，有的部位无磁粉。和紫外线探测仪不同的是，紫外线探测仪需要使用者要与主观的颜色进行对比以确定纸币的真伪，而展测仪则无需凭藉人的判断能力