Sure. I would be happy to do that, Mr. Chair.
In fact, I think there's a fairly good description from your previous witness in November, Professor Hannem. She went through that in some detail.
How it works is that you use a piece of material to swab a surface and hopefully pick up traces of, let's say, cocaine. You insert that into the machine. The machine heats it up to vaporize what's on the swab. That gas goes into what's called a “mass spectrometer”. It's this little tube, and it's ionized with an ionizing source, and then there's an electrical field in there that drags the ions down the tube.
Depending on how big they are, what shape they are, or how much they weigh, they go faster or slower. Depending on what the molecule looks like, it can arrive more quickly or more slowly at the detector at the far end. That gives you a little graph, where you'll see that this one arrives, then that one, and then that one, etc. That's essentially how it works. We pick up electrical signals when the ionized molecules bump into the far end.