Three ways, detailed below:
Click on the "Col Smp" icon:
Go to the collect menu and down until "collect sample" is highlighted:
The Impact 410 interface is slightly different:
It takes a few seconds for the instrument to scan the spectrum. The image below shows what the screen looks like while it is scanning.
Below is a correctly scanned spectrum of an alcohol. If it does not look like this, for instance, if it is a straight or jaggedy line, someone probably left a sample in the instrument when the background was run.
Below is what it can look like if you collect a sample over an improper background - this is NOT what you want it to look like.
