4,255 ppm to PSU

4,255 ppm = 4.276 PSU

ppmPSU
4,240 ppm4.261
4,245 ppm4.266
4,250 ppm4.271
4,2554.276
4,260 ppm4.281
4,265 ppm4.286
4,270 ppm4.291

4255 ppm = 4.276 PSU

Formula

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