The whole chamber plus isolation must be held in place on the base plate. To do that I cut two stripes of flat aluminium and added four threaded rods to it. This will serve two purposes:
- hold the chamber in place
- hold down the lid
The threaded rods were glued in with screw locking glue:
The lid is held in position with 4 L-shaped pieces of aluminium. Two of them have cutouts to make it easier to pick up the lid.
The GUI was done with Qt. This was the first time I used the QSerialPort class and it works very well. Two plot windows for temperature and power plots are still missing, but the temperature readings can already be seen in the schematic view:
The arduino sketch is sending strings of raw data which can be seen in the bottom part of the window. These are parsed and displayed in the schematic view. I used the NIST ITS-90 Thermocouple Database tables (for type T in my case) for the ADC voltage reading to temperature conversion. This is done on the PC side so I don't have to worry about performance.
The thermocouple positions are
- between the heaters to limit the maximum temperature that the galden is exposed to at the chamber's bottom,
- right below the PCB,
- and at the chiller exit.
Heater and chamber thermocouples can be seen in the pictures above, the chiller is not mounted yet.