> In fact, it has been estimated that the results [for the Scoville scale] from different laboratories could vary by as much as 50 percent.

Not really that important. +/-50% is no big deal. The range is pretty wide. Even with 50% error you're in no risk of confusing, say, a Jalapeno pepper for Cayenne. And those are both way-too-spicy peppers to my mom, or kinda everyday peppers in my household.

The hot sauces that I personally use cover about three orders of magnitude, I'm sure.