A number of commercially available person-support apparatus include an air filled person support surface. Normally, the air within the person support surface can be regulated depending on the patient's requirement. It is preferable that the air pressure inside the person support surface be maintained such that the contact area between the patient and the person support surface is therapeutically optimal to minimize peak interface pressures. Air pressure should also be sufficient so that the weight of patient preferably does not cause the patient to touch the firm, structural bottom of the person support surface. An optimum value of pressure within the person support surface is called as the pressure relief set point. Pressure relief set point values can vary from patient to patient depending, for instance, on their weight as well as potentially other variables. While various systems and methods have been developed to accommodate patients of various weights on a person support surface in an optimal manner, there is still room for improvement. Thus a need persists for further contributions in this area of technology.