开源色度计

该项目详细介绍了一个开源色度计，它由开源电子设备和 3-D 可打印组件制成。这是使用开源硬件降低科学设备成本的大型项目的一部分。^[1]

来源
Anzalone GC、Glover AG、Pearce JM。开源色度计。传感器。2013；13（4）：5338-5346。doi:10.3390/s130405338开放访问

抽象的
历史上与研究相关的复杂传感器和工具的高成本限制了它们的采用，仅限于一小部分资金充足的研究人员。本文提供了一种将开源方法应用于色度计设计和开发的方法。讨论了仅使用开源硬件和软件解决方案以及现成的分立元件的 3-D 可打印开源色度计，并将其性能与商用便携式色度计进行了比较。使用为封闭回流化学需氧量 (COD) 方法准备的商业小瓶评估性能。这种方法将可靠的封闭回流 COD 的成本降低了两个数量级，使其成为绝大多数潜在用户的经济替代方案。开源色度计表现出良好的可重复性，可作为进一步开发和推导设计的平台，用于其他类似目的，如比浊法。这种方法保证了最需要的人、欠发达国家和发展中国家的实验室能够前所未有地获得基于低成本传感器的复杂仪器。

关键词

开源；开源硬件；比色法；鳕鱼；阿杜诺; 重复说唱；3D打印机；开源传感器；化学需氧量；开源色度计

简介

比色分析方法可能是确定溶解物质浓度的最常用方法。许多溶解的物质吸收特定波长的光，当光通过给定长度的溶液时吸收的量随着物质浓度的增加而增加；较高的浓度比较低的浓度吸收更多的光。吸收和浓度之间的关系由Beer-Lambert 定律[2]定义。

使用色度计或分光光度计来测量特定波长的吸收。通常对光进行过滤以仅允许在所测物质的吸收峰波长处出现窄带光。该设备通常以浓度单位报告结果，但也报告吸光度单位或透射率。

设计文件：http ://www.thingiverse.com/thing:45443

固件：http: //github.com/mtu-most/colorimeter

BOM

• 阿杜诺
• Adafruit 液晶屏 ( http://www.adafruit.com/products/772 )
• LED 的峰值约为 606nm（如：LEF3833 http://www.jameco.com/Jameco/Products/ProdDS/333665.pdf）
• 适合您选择的 LED 的电阻器
• TSL230R光频传感器
• Proto board (like: http://radioshack.com/product/index.jsp?productId=2102845&znt_campaign=Category_CMS&znt_source=CAT&znt_medium=RSCOM&znt_content=CT2032230)
• Conductors (Cat 5 cable works great)
• Black ABS or PLA filament
• 12 M3 screws (just about any length; 10-12mm is good)
• 12 M3 nuts
• 20 M3 washers

Instructions

1. Print the parts and clean them up so everything fits together nicely. Push M3 nuts into their appropriate slots at each corner of the case body - slots open to interior.
2. Cut the proto board down to size (about 27mm x 46mm) and drill holes to match those in the sides of the case.
3. Loosely attach the boards to the interior of the case with a couple screws each and push the cuvette holder into place (no cover) and mark the approximate locations where the sensor and LED must be placed on the boards to align with the windows in the cuvette holder.
4. Remove the boards from the case and solder the components to their respective boards at the points marked. Leave the LED leads a bit long so it can be moved to aim the beam through the hole.
5. Solder the conductors per the schematic. (The io pins can be soldered to directly on the LCD shield if you're careful, otherwise different means will be required, like not using the shield as a shield.)
6. Fit the boards back into the case, this time firmly.
7. Download and install the firmware on the Arduino.
8. Fit the LCD shield and power the device (surplus wall wart of appropriate voltage or USB power will work).
9. Place the cuvette holder back into position (no cover) and use the menu system to select "Calibrate". The LED will illuminate for a few seconds - make sure that the majority of light passes as straight as possible through the cuvette holder windows and impinges upon the sensor. If the LED/sensor are high or low, reshape the cuvette windows with a small rat tail file or suitably sized drill bit.
10. After the LED is properly aimed, remove the cuvette holder and align and affix the cover to the case with four M3 screws and washers.
11. Push the cuvette holder through the opening in the cover and check that the lid fits nicely into recess.
12. Follow the appropriate protocol for calibration (yet to be built into the firmware - forthcoming).

Applications

• COD^W

Media

• Joshua M. Pearce, "Open source 3D printing allows you to print your own cheaper health devices", Conversation, Feb. 28, 2014.
• 3D printing in the lab- Biolegend

See also

• Open-source Lab
• Open-source mobile water quality testing platform
• Open-Source Photometric System for Enzymatic Nitrate Quantification
• Open source optics
• Building research equipment with free, open-source hardware
• Open source science
• Open source 3-D printing of OSAT
• Open-source hardware

References