Example DO deficit of paddlewheel A test c1 at 62 rpm speed. The shape of the plots depend
on the estimation of saturation capacity Cs *, from which DO measurements are referenced to determine
DO-deficit. The plots should be linear when the DO-deficit is on a logarithmic scale, but raw data was
non-linear (upper curve) because the estimation of Cs * was incorrect. Least squares fit of the slope of the
log of DO-deficit vs elapsed time (lower curve) determined re-aeration time-constant (1/KLa).