This Heat Conduction Isothermal Calorimeter is used to determine the heat flow rate of a specific process or reaction, in my case it will be used to measure the heat rate of hydration of cement in the field of Civil Engineering.
The design is based on a paper by Dr Lars Wadsö published in the Journal of Chemical Education.
I built this device for students use in the Materials Science Lab (especially for a PhD student for her experiments) in Alexandria University, Egypt.
ATMEGA32U4 USB Board
Data Converters / Analog to Digital Converter ICs (ADCs)
I am trying to organize this build in a single place on my weblog and will be updating it regularly with more diagrams and eventually some Arduino/Teensy source code for data acquisition into the SD card.
I'm busy at college so didn't have the chance to update the log much further.
I created a PCB to plug-in the Teensy 2.0 board and handle external power using a single cell 3.7V LiPo 4000mAh, running the Teensy at 3V instead of 5V will consume less power and give the battery roughly 6-8 days of continuous data logging to the SD card. During the experiment we experienced periodic loss of power so that's why we are adding external power source.
Also, I believe the battery powered device will reduce lots of the noise from the AC adapters.
I'll be adding more photos after I finish etching the board and soldering the components.
The prototype is complete now, I calibrated my sensors with water in the reference vial so this calibration coefficient will work with solution but I will have to re-calibrate it for cement.
The calibration for cement will require filling the reference (inert) vial with Sand or NaCl. Because the specific heat capacity for water is 4182 J/kg while Concrete is 880 J/kg which matches that of Salt and NaCl of 880 J/kg. Sand will be accessible in our Lab, and its specific heat capacity is 830 J/kg.
A PhD student at my faculty is using the device now to perform the heat of hydration of cement experiment over an interval of 7 days. The data is being logged to a micro SD card into a CSV file every 5 seconds (which can be opened via libreOffice Calc or any spreadsheet program).
I'll be adding more specific details about the build and the calibration process.