The instrument does respond more strongly to an increased volume. However, we don't use that in our machines. It's either yes or no, above a certain threshold. We're looking for such tiny quantities, that if you have a nanogram here or two nanograms over there, it's still a very small amount. The volume that you might see from these tests is not a good indicator of what might be in the bag.
On March 20th, 2018. See this statement in context.