Figure 1. Shows the concentration of CO (open circles) in parts per million (ppm) interpolated from the graphic data of Frink et al. This figure also compares COHb % calculated at 40% inspired oxygen from these data (small triangles) using the CFK equation for comparison with the experimental COHb % taken from the graphic data of Frink et al. The experimental COHb data correlate well with those predicted by the CFK equation.