水箱深度传感器

       水是一种宝贵的资源在世界的许多地方,许多人依靠水箱补充他们的水供应通过存储收集雨水或水从井注入或孔。但你如何衡量一个柜是有多满?水箱是由不透明的材料,以防止藻类增长和经常保持封闭起来,以防止蚊虫侵扰或访问由小型啮齿动物所以身体不便往里看。此外,有一种方法来测量槽深度电子打开了一个世界的可能性如自动控制泵上水箱当他们得到低或禁用灌溉系统当没有足够的水是可用的。

       最明显的方法测量槽深度是通过将一系列导电皮卡各种高度的容器内并测量它们之间的电阻。例如,放置十暴露终端连接到一个长度相等的间隔材料如PVC管材和插入到槽将允许您测量深度在10%增量通过读取阻力之间的底部终端和每个终端上面。这种方法的缺点是,你需要做大量的布线和您还需要读一个模拟输入的每个用户的终端——虽然大多数Arduino设计没有超过6个模拟输入。

       这个项目略有差异。它使用一个装置称为微分压力传感器来测量水的压力罐的底部,并从计算完整的水箱是如何。水压力增加约9.8067 kpa每米的深度,这样一个完整的柜2米高将会有一个压力的底部约19.6134 kpa高于环境大气压力。“以上环境大气压力”部分是重要的:它没有足够的简单测量压力罐的底部,因为不同气候条件将改变阅读。这就是为什么这个项目使用“微分”压力传感器,有两个入口。留下一个入口开放的氛围和连接其他底部的坦克的传感器将输出两者的区别,自动补偿不同空气压力和给一个常数,常数深度阅读。

Water is a precious resource in many parts of the world, and many people rely on water tanks to supplement their water supply by storing collected rainwater or water pumped from a well or bore. But how do you measure how full a tank is? Tanks are constructed of opaque material to prevent algae growth and often kept closed up to prevent mosquito infestation or access by small rodents so it's inconvenient to physically look inside. And besides, having a way to measure tank depth electronically opens up a world of possibilities such as automatic control of pumps to top up tanks when they get low or to disable irrigation systems when not enough water is available.

The obvious way to measure tank depth is by placing a series of conductive pickups at various heights inside the tank and measure the resistance between them. For example, placing ten exposed terminals at equal intervals attached to a length of material such as PVC tubing and inserting it into the tank will allow you to measure the depth in 10% increments by reading the resistance between the bottom terminal and each of the terminals above it. The downside to this approach though is that you'll need to do a lot of wiring and you'll also need to read an analogue input for every individual terminal - while most Arduino designs have no more than 6 analogue inputs.

This project works a little differently. It uses a device called a differential pressure transducer to measure the water pressure at the bottom of the tank, and from that to calculate how full the tank is. Water pressure increases by about 9.8067kPa per meter of depth so a full tank 2m tall will have a pressure at the bottom of about 19.6134kPa above ambient atmospheric pressure. The "above ambient atmospheric pressure" part is important: it's not enough to simply measure the pressure at the bottom of the tank because varying climate conditions will alter the reading. That's why this project uses a "differential" pressure transducer that has two inlets. By leaving one inlet open to the atmosphere and connecting the other to the bottom of the tank the transducer will output the difference between the two, automatically compensating for varying air pressure and giving a constant reading for constant depth.