We introduce the concept of neutron-proton two-particle units ($np$-Weisskopf units) to be used in analysis ($^3$He,$p)$ and $(p,^3$He) \added{reactions on nuclei} along N=Z line. These are presented for conditions relevant $(n,j,\ell$) orbits expected from $^{16}$O $^{100}$Sn. As is case Weisskopf electromagnetic transitions, $np$-WU's will provide a simple, yet robust, measure isoscalar isove...