If someone said, "It found 100 times more water in the beads than has ever been measured", you could (pedantically)object that that amount has been measured, or the statement couldn't be made. With the addition of "before", there's no logical contradiction.
A: "Has this amount ever been measured."
B: "Yes, we just did that. Do you mean before?"
A: "Has this amount ever been measured before?"
A: "Had this amount ever been measured before?"
B: "Before what? Do you mean before this time? No, that's what we're saying. This amount has never been measured before."
- For Teachers