I am an undergraduate Mechanical Engineer and currently I am using a laser which heats and melts a surface of any material (plastic, metal etc) which is formed in powder. Although, I have managed to melt some plastic's powder, I want to put more accuracy in the control system of the laser with the temperature of the surface which is being heated.
To be more specific, I want to measure, relatively accurately, the heated material's temperature and when the temperature reaches the melting point I want the laser to be turned off. I googled about the thermal radiation effect and I found about the pyrometer device. I would like to ask if there is a pyrometer which is compatible with Arduino/Tiva microprocessor with a normal range of temperatures. I found some pyrometers/contactless thermometers that can measure up to 380 degrees Celsius which is not enough since the melting point of aluminum is 660 degrees (I want to use later aluminum).
Any suggestions?
Thank you for your time and for your answer in advance,
Chris
EDIT (after Jonk's suggestion):
Chamber:
The chamber currently is in room conditions (20-25 degrees of Celsius) as I just finished building it but I was thinking of inserting an inert gas later to prevent oxidization of the product (in room temperature).
Laser:
The laser is a YLIA M20 with a wavelength of 1064nm and the diameter of the beam is around 1mm. I use it at the maximum power at 20W. I want to measure the temperature of the area that the beam heats (local measurement). The laser distance between the laser and the surface is not fixed but after some experiments I made I calculated that it would be best around 100mm.
Budget:
The budget is around 500-1000 euros. If my idea for the pyrometer works and is a good solution it could be higher (1500-2000 euros).
Material:
The materials are formed in thin powder and supposed to be of any kind (plastic, metal, ceramic, glass). I cannot tell you with certainty the exact types yet because I don't know in what range I am going to use the machine I am going to build, but for a start I want to be able to measure 700 degrees of Celsius. The minimum emisivity could be at 0.5 since I don't use polished materials.
Microcontroller:
The laser's position is controlled by two motors (X and Y axis) via Arduino boards. The Z-axis of the laser is controlled through the movement of the base that hold the powder (the height of the laser in regard to the ground is fixed). The Z-axis' motor is also controlled with an Arduino board. The Arduino boards are then connected via an electronic system with a pmac board, which I use to write G code to control the movements of the laser. This whole set-up has been implemented and it works. So what I want is a control system that can also get feedback from the heated points (so for example if the melting is correct the laser can move from point to point). The microprocessor board compatibility with a non-contact thermometer is a must so I can use it in the system that I already have created.
In case I missed again something, please tell me to include it in my question.
Best Answer
The easiest way to go about solving this is to have information about the material to be melted pre-loaded within Arduino code so that you can calculate exactly when to shut the laser off by also knowing the specifications of the laser. In other words, if you know how the thermal characteristics of the laser from the datasheet, you can use thermodynamics equations to calculate precisely how much time the laser needs to be turned on. The equations can be implemented within Arduino code and can directly turn the laser on and off. Again, I suggest creating a class within your code to organize the different materials that you will be melting so that all of the important parameters are included. Finally, create an interface for the user to input the type of material to be melted so that the systems knows exactly which formulas to use within code and control the laser's operation.