[ISL]

A pound of force is defined [1, 2] as 4.448222 N . No gravity necessary (but the IPK is, until the upcoming redefinition of the SI).

Yes, that definition was reached using a notion of "standard gravity", but once fixed, it is nothing but a number.

[1] https://physics.nist.gov/cuu/pdf/sp811.pdf [2] https://en.wikipedia.org/wiki/Pound_(force)

[ricardobeat]

Still not any more precise than kg to measure human weight (unless you position the human at the exact right spot on earth).

[ISL]

A properly-calibrated scale/balance will correctly determine the mass of any object in any gravitational field (gravity gradients excepted).