Make a simple hygrometer for 0$ !! (great for your childrens!) by kondzio29

创客教育——0成本制作简单湿度计

（译者按：现在创客教育遍地开花，动不动就喊机器人、开发板、编程等，似乎不用高科技的东西就是逗比。大部分人都抱有这种态度，能吃猪肉就不需要见过猪跑，而期望横行新兴教育行业。当问及某个套件的工作原理时，要么支吾打岔，要么说这是高科技结晶云云，而心理要么乞求赶紧打发掉这难题，要么就开始忌恨发问的愣头青……说了这么多，我只想说条条道路通罗马，不一定非要靠某个套件就能达到目的，虽然商人纯粹就是希望顾客这么想的。）

原文出处：http://www.instructables.com/id/Make-a-simple-hygrometer-for-0-great-for-your-chil/?ALLSTEPS
原作：kondzio29
译者：Kalimov

Since I posted my last instructable about simple science (you can check it out here) it get 41,501 views, so I decided to post another one. And today you will learn how to make a simple hygrometer, Another project that is fun to make with kids, and it is educational as well.
自从我登出了上个教程，关于简单科学的（译者注：0成本制作显微镜http://www.instructables.com/id/DiY-Microscope-for-0-great-for-your-childrens/），它得到了强烈反响，于是我决定登出另一个。今天你会学到如何制作一个简单的湿度计，和孩子一起来制作时一件快乐的事，也能作为教学用途。

If you're curious about how it works, check last step ;)
如果你觉得好奇，想知道它的工作原理，那就直接跳到最后一步。

Step 1: You will need...

一、你需要……

Here are the things you will need to make the hygrometer:
下列是你需要用来制作湿度计的东西：

Scissors
Sharpie, or a pen
piece of paper (preferably thicker than regular printing paper, i used 180g/m^3)
piece of cardboard/thin plywood/something that you can pin the pin into
ONE hair, preferablu longer than mine - about 5-7 cm long
1. 剪刀
2. 记号笔，或钢笔
3. 一张纸（用厚纸好过普通打印纸，我用的是180克/平方米规格的）
4. 一片卡纸板/薄纤维板/或者你能把图钉按进去的东西。
5. 一条头毛，比我的长就好了——大约5-7厘米。

I Highly recommend to use horse hair. It reacts better and more noticeably than human hair.
我强烈建议使用马毛，比人类毛发来说反应更好，更显眼。

But unfortunately my horse was drinking beer in the pub.... so I used my hair. ;)
但不走运的是我的马子正在酒吧里喝酒……于是我用了自己的。（译者注：你那匹“马”在酒吧里会否突然呛酒？还有，你不会从她的梳子上面拔毛？！）

Step 2: OK! Now we can start learning.

二、好吧，开始学怎么做！

Try to draw an arrow on paper, it don't have to be big, look at mine arrow, it can be similar. Then you have to cut it out using scissors.
在之上画一个箭头，不需要大，就像我的箭头那样。然后就用剪刀把它剪下来。

Remember! always be careful using scissors and don't let kids to play with them when you are not around.
记住！用剪刀时永远要小心，你不在的时候不要让孩子拿它玩耍。（译者注：做创客教育的莫要忽视这个细节。）

Now the most important part, You have to make hole in arrow and make a pivot point. The hole need to be a little bigger than pin so the arrow can move freely. You can check it by twisting the pin - when arrow always point down no matter which way you turn the pin.
现在是最重要的部分，在箭头上弄个洞做成个旋转支点。洞眼需要稍比图钉大，那么箭头就能自由转动。通过旋转图钉就能检查结果，无论你怎么转图钉箭头会一直指向下面。

When you finish arrow pin it to the cardboard/plywood and check if the arrow spins freely.
当完成箭头后，把它钉在卡纸板/纤维板上，看看它能否自由旋转。

Step 3: Tape the hair to the arrow and cardboard.

三、把毛发粘在箭头和卡纸板上

Cut small piece of tape and stick it to the hair and then to the arrow. Pin the arrow to the cardboard and tape the other end of hair to it.
剪下小小一片胶带纸，将其粘在毛发上然后再贴到箭头上。将箭头钉在卡纸板上，然后将毛发另一端粘上去。

Basically you finished ;) But I have added some graphics to it, so it look quite better.
基本上就完成了，但我还是加了点图像上去，让它看起来好一些。

Step 4: But... How it works?

四、可是……它的工作原理是？

Here is how it works:
下面是它的工作原理：

Hair have special hidden ability to shrink when dry and expand when wet. Using this fact, when there are more moist in air the hair will be longer and the arrow will point more downwards. When the air is dry, the hair will shrink and move arrow upwards.
毛发有个特殊隐藏属性，当干燥时收缩，湿润时则延展。利用这个事实，当空气中有较多水分时，毛发会边长，那么箭头将向下指。当空气干燥时，毛发会收缩，将箭头扯上去。

The longer the hair is the more visible is arrow movement. You can use horse hair to make it more visible, since horse hair reacts stronger on humidity changes and moves arrow more visibly.
越长的毛发，箭头动作约明显。用马毛会更明显，因为马毛在湿度变化时反应会强烈些，让箭头移动得更明显。

It's a project great to make with children and show them some science ;) but you can use it to check the changes in air humidity in your room ;)
这是个和孩子一同制作的很好题材，能在科学活动中展示。但你还是可以用它来测量房间内的空气湿度变化的。

（译者后记：其实用于气象测量的机械指针湿度计用的就是这种结构。不过国人小孩从小被教育为多听少说，自然就少发问了，对这些简单机械除了惊讶膜拜就没有更多了。创客教育不是灌输知识，而是要煽动他们发问的天性，要做到像现在的青少年问爸妈要钱那样自然。（办公室同事：你这是夸还是骂？！））