644 g/kg to PSU

644 g/kg = 647.156 PSU

g/kgPSU
629 g/kg632.082
634 g/kg637.107
639 g/kg642.131
644647.156
649 g/kg652.18
654 g/kg657.205
659 g/kg662.229

644 g/kg = 647.156 PSU

Formula

1 g/kg ≈ 1.0049 PSU · 1 mg/L ≈ 0.001 PSU · 1 ppm ≈ 0.001 PSU (dilute aqueous approximation)