Instructions on how to make the case
For each sensor case you will need to create 3 plastic components and 2 gaskets. The plastic components are the case’s bottom, the top and the sensor holder. The gaskets are used to close off the case and to seal the sensor. In the past, I have cut the gaskets from 2mm silicone sheets (sh 40) using a leather hole punch and razor blades and milled the case from PMMA. Currently, I am in the process of testing the device using a 3D printed version created using a Formlabs printer.
When assembling the device I used 12 stainless steel (INOX) 4 mm screws, 24 washers and 12 nuts. I first I screw together the case and visually inspect the gasket to make sure that there is enough pressure on all sides to cause slight deformation. Then I screw the sensor holder and gasket in place. Again I check to make sure that the sensor gasket is slightly deformed. To disassemble the device I first take off the sensor holder and then open the case. It is very important to put pressure on the gaskets in this order because if pressure is applied in the opposite order the case may not receive enough pressure to seal, or the sensor holder could be under too much force and break.
In theory it would be possible to glue the sensor to the hole in the case and not use the sensor holder or gasket. However, this has not been tested. If you are planning on testing the device this way I would recommend leaving enough cable on the temperature sensor so that the data can be easily downloaded from the MCHCK.