  It is desirable to relate entanglement of many-body systems to measurable
observables. In systems with a conserved charge, it was recently shown that the
number entanglement entropy (NEE) - i.e. the entropy change due to an
unselective subsystem charge measurement - is an entanglement monotone. Here we
derive finite-temperature equilibrium relations between Renyi moments of the
NEE, and multi-point charge correlations. These relations are exemplified in
quantum dot systems where the desired charge correlations can be measured via a
nearby quantum point contact. In quantum dots recently realizing the
multi-channel Kondo effect we show that the NEE has a nontrivial universal
temperature dependence which is now accessible using the proposed methods.
