时差N小时 兑钞机是如何识别钞票的?

Money Changers ever wonder how a money changer machine knows if you've given it a one, a five or a ten dollar bill? When a bill is inserted into a money changer machine, it disrupts a light beam from within the machine.

兑钞机是如何辨别塞进去的钞票是一元、五元、还是10元？兑钞人员也曾对此感到疑惑吗？当纸币被塞进一个兑钞机时，阻挡了机器内部的光束。

This action triggers the motor to pull the bill into the money changer. The machine then begins a procedure by which it first makes sure the bill is actual currency and then determines the denomination¹ of the bill. With a computer chip and measuring devices, the money changer checks the length, width and thickness of the bill.

这个动作触发电动机把钞票拉进机器内。然后机器开始执行一系列的程序：首先确定纸币是否真实，然后检查纸币的面额。兑钞机通过一块电脑芯片和测量设备来检测钞票的长度、宽度和厚度。

If the bill is not the exact length and thickness it should be, the changer will reject it and refuse to give you any change. The sensors² that evaluate the bill are so sensitive that even an old, wrinkled bill usually will not pass this authenticity³ test because it will not measure precisely⁴ the same as a crisp, new bill.

如果长度和厚度不达标，兑钞机就拒绝兑换。对钞票进行估价的传感器灵敏度极高。即使是旧的、有褶皱的钞票通常也不会通过验证检测，因为这样的钞票的检测结果达不到崭新钞票的标准。

After the machine measures the bill's width, length and thickness, it optically scans the bill to determine if it is a one, five, or ten dollar bill. The machine makes this decision by “reading” how much ink is in different places on the bill.

兑钞机测量钞票的长、宽以及厚度之后，便开始扫描钞票，判断它的面值是一元、五元还是十元。机器通过“读出”钞票上不同部位的油墨含量来判断钞票的面额。

The U.S. treasury⁵ department uses specially⁶ manufactured ink that has unique magnetic properties. The machine's optical scanner measures this magnetic ink. And because a one dollar bill has a different ink pattern than a five or ten dollar bill, the computer inside the machine is able to differentiate⁷ between these denominations⁸ with a quick scan.

美国财政部门利用专门制造的油墨来印钞，这种墨水的特性是具有磁性。兑钞机内部的光扫描器能测量这种磁性油墨。因为一美元钞票上的油墨图案与五美元的不同，兑钞机内的电脑能通过快速扫描来识别不同面值的钞票。

1 denomination   

n.命名，取名，(度量衡、货币等的)单位

参考例句：

• The firm is still operating under another denomination.这家公司改用了名称仍在继续营业。
• Litre is a metric denomination.升是公制单位。

2 sensors   

n.传感器，灵敏元件( sensor的名词复数 )

参考例句：

• There were more than 2000 sensors here. 这里装有两千多个灵敏元件。 来自《简明英汉词典》
• Significant changes have been noted where sensors were exposed to trichloride. 当传感器暴露在三氯化物中时，有很大变化。 来自辞典例句

3 authenticity   

n.真实性

参考例句：

• There has been some debate over the authenticity of his will. 对于他的遗嘱的真实性一直有争论。
• The museum is seeking an expert opinion on the authenticity of the painting. 博物馆在请专家鉴定那幅画的真伪。

4 precisely   

adv.恰好，正好，精确地，细致地

参考例句：

• It's precisely that sort of slick sales-talk that I mistrust.我不相信的正是那种油腔滑调的推销宣传。
• The man adjusted very precisely.那个人调得很准。

5 treasury   

n.宝库；国库，金库；文库

参考例句：

• The Treasury was opposed in principle to the proposals.财政部原则上反对这些提案。
• This book is a treasury of useful information.这本书是有价值的信息宝库。

6 specially   

adv.特定地；特殊地；明确地

参考例句：

• They are specially packaged so that they stack easily.它们经过特别包装以便于堆放。
• The machine was designed specially for demolishing old buildings.这种机器是专为拆毁旧楼房而设计的。

7 differentiate   

vi.(between)区分；vt.区别；使不同

参考例句：

• You can differentiate between the houses by the shape of their chimneys.你可以凭借烟囱形状的不同来区分这两幢房子。
• He never learned to differentiate between good and evil.他从未学会分辨善恶。

8 denominations   

n.宗派( denomination的名词复数 )；教派；面额；名称

参考例句：

• Christians of all denominations attended the conference. 基督教所有教派的人都出席了这次会议。
• The service was attended by Christians of all denominations. 这次礼拜仪式各教派的基督徒都参加了。 来自《简明英汉词典》