苹果手表又曝“纹身门”

With a variety of bands, and price tags ranging all the way from $349 – $17,000, there’s an Apple Watch for everyone. Except, possibly, the heavily tattooed.
面向大众推出的Apple Watch，款式多样，价格从349美元到17000美元不等。现在它却被发现可能不适用于有大量纹身的人。

That’s according to a new thread on Reddit which claims that several tattoo-sporting Apple Watch customers are having trouble using the device, because the wearable’s wrist-detection feature gets confused by the way in which tattoos reflect the green and infrared light emitted by the Watch.
Reddit上的一个新帖称，几个有纹身的消费者发现他们的Apple Watch无法正常使用，原因在于纹身会反射手表发射出的绿光和红外光，导致该可穿戴设备的手腕监测功能被干扰。

The result? People with tattoos don’t get notifications, unless they move the Watch to an un-tattooed area, or turn off wrist detection. Not exactly ideal for those with full sleeves!
结果怎么样？有纹身的人除非把手表戴在没有纹身的地方，或者关闭手腕监测功能，否则他们无法接到通知。这对于整个手臂都有纹身的人来说不太可能。

“I thought my shiny new 42mm [Watch] had a bad wrist detector sensor,” writes one user. “The [W]atch would lock up every time the screen went dark and prompted me for my password. I wouldn’t receive notifications. I couldn’t figure out why especially since the watch was definitely not losing contact with my skin. [A]lso I couldn’t find anything online with people experiencing this issue. I was about to give up and call Apple … when I decided to try holding it against my hand (my left arm is sleeved and where I wear my watch is tattooed as well) and it worked. My hand isn’t tattooed and the Watch stayed unlocked. Once I put it back on the area that is tattooed with black ink the watch would automatically lock again.”
“我觉得我亮眼的新42毫米手表的手腕监测功能有问题，”一名使用者写到。“屏幕一黑手表就锁上了，并提示我输入密码。我收不到通知。手表并没有与皮肤失去接触，所以我弄不清原因。网上也没有人提出同样的问题。我打算放弃并且给Apple公司打电话。我的左臂上有纹身，戴手表的位置也有。我试着把手表拿在手里，它就可以正常使用了。我的手上没有纹身，手表就一直处于开启状态。一旦我把它放在有黑色纹身的地方，它就又自动锁上了。”

As a possible explanation, another Redditor writes that:
一位网友给出了较为合理的解释：

“Oxyhemoglobin has several local peaks of absorbance which can be used for pulse oximetry: one green, one yellow, one infrared, etc. Apple uses the ones at infrared and green parts of the spectrum. Now, here’s some key facts. Melanin and ink are both equally good at absorbing frequencies over 500nm, which sadly includes the green. But, melanin’s absorbance falls down so rapidly that by the infrared end of the spectrum its hardly absorbing anything at all. That, combined with the fact that Apple adjusts the sensitivity/light level dynamically means infrared is probably black people friendly. Ink has a much more gradual fall off, so even infrared might not work for them.”
“氧基血红素能快速吸收绿光、黄光和红外光等，可用于脉搏血氧测量。苹果公司就利用了其可吸收光谱中的绿光和红外光的性能。现在，有几个关键原理。黑色素和墨水都易于吸收频率高于500纳米的光，可悲的是，这其中就包括绿光。但是，黑色素的吸光度下降迅速，到光谱红端它几乎什么都不能吸收了。再加上手表能不断地调节感光度，这就意味着红外光可能对黑皮肤较为友好。而墨水的的吸光度下降平缓，因此连红外光也无法为其工作了。”

While it’s possible to turn off the wrist detection feature, this also stops Apple Pay from working. We’ve reached out to Apple to ask if this is a problem that’s been reported elsewhere, and will update this post when we hear back.
尽管能关闭手腕监测功能，但手表的支付功能也就随之不能使用了。我们已经联系了苹果公司，询问了其他地方是否也有同样的问题。收到回复后，会为您带来后续报道。

Tattoo-gate, anyone?
苹果纹身门，谁能解决这个问题呢？

Vocabulary

malfunction：发生故障；不起作用

infrared light：红外光

spectrum：光谱