for rectilineal axes of co-ordinates, the distance of a point from the axis of ordinates measured in a direction parallel to the axis of abscissae, which is usually horizontal. The sign convention is that measurements to the right from the axis of ordinates are positive, measurements to the left negative. Plural abscissae.
Plot a calibration graph using the mean peak heights or areas of the calibration solutions as the ordinates and the corresponding concentrations in µg/ml as the abscissae.