Pressure has an effect on the size of an absorber. At high pressures, the size of the absorber is reduced, as the molecules in the absorber are more tightly packed together. This means that more molecules can be present in the same volume, leading to a smaller absorber size. At low pressures, the molecules in the absorber are more spread out, resulting in a larger absorber size. The effect of partial pressure on absorber size is similar, as partial pressure is a measure of the pressure exerted by one gas in a mixture of gases.