Print quality control for a xerographic printer having an AC development field

In a xerographic development system wherein toner is conveyed from a donor member over a development gap to a charge receptor by a development field in the development gap to develop an imagewise-discharged image on the charge receptor, the development field having a DC bias and an AC component having an amplitude associated therewith, a method comprising the steps of:

• measuring actual reflectivities of a first test patch having a first target halftone density, thereby determining a first error, and a second test patch having a second target halftone density, thereby determining a second error;
• if the first error and the second error have the same sign, determining a change in DC bias which will substantially cure at least one of the first error and the second error;
• and
• if the first error and the second error have different signs, determining a change in a parameter which will substantially cure at least one of the first error and second error, the parameter being one from a group consisting of DC bias, amplitude of AC component, initial potential on the charge receptor, and power associated with imagewise discharge of the charge receptor.