Step 2: Column Assembly for measuring gasses from 3D Printing materials
Measuring gasses with the correct equipment is very simple. We set up a column or tube for the gasses to pass thru undisturbed by surrounding forces such as fans and wind. We allow for air to be pulled in by thermals created by the hot end. We then create an opening or escape equal to the physical proportion of the heating element and at that opening, we place our measuring sensor. As the temperature increases, the air heats, warm air rises and gasses lighter than air are carried along the path. The mixture of hot air and gasses passes by the sensor element creating a change in the sensor that corresponds to an increase or decrease in the displayed reading. Scientist write entire books on this process, but at the end of the day it's......Hot air, gasses, sensor and a reading.
The column we used is a simple 2 cubic foot acrylic assembly. 4 each pieces of clear acrylic and one each 12" square piece of plastic to serve as a lid. Clear acrylic was selected as we would video capture the degradation of the material at the same time temperature was increasing. This way we could spot the affects of degradation and correlate to some degree the amount of gasses detected.
The lid is cut at 5" in at the corner. This allows us to make a slot for the exhausting air and gas mixture. The 4 panels are glued or taped at the seams to minimize leakage. We selected glue as we were going to use a power washer to clean the column after each test. We also strapped large wire ties about the unit to help maintain stability.
Each bottom corner has a one inch plastic standoff or mounting foot to raise the column off the table about an inch along the bottom. This allows air to be drawn in as thermals start under increasing temperature.
- 4 each 12 x 24" acrylic panels 1/4" thk
- 1 each 12" square plastic for the top
- 4 each spacers of mounting feet
- Glue for the seams
- Support Straps - We used 14" long ties