What official standards do you have to conform to, and what do they say? Example, is this for environmental release, and do the EPA standards specify you have to do all these standards. Then yes, you do, of course -- why would you ask? Would you ask the world, "Its 3am, do I have to stop at red lights, no one else is around, who's gonna know?"
If you're not under some sort of rigid legal obligation, dd you still say, or imply, that you were? Are you following a protocol based on EPA standards, for some internal use, and do you claim (or are people assuming) that you're working to that standard?
Briefly yes, when you try to perform an analytical test, you want to be sure your instrument is working correctly, so some testing of a known standard is needed. But how much, and how often, we kinda just made up some of those rules.
What more can you tell us, about your application, to help us figure out the reasons?