Who can help me to introduce the role of pre-pressure, panning and range of high speed tablet press, thanks!

The role of pre-pressure is to discharge the air in the material before the material enters the main pressure, so that the material enters the main pressure is more compressible, and plays the role of pre-pressure, just like roughing and finishing; panning is generally not necessary to move, it is used to adjust the depth of the upper punch into the hole of the center die, generally have been adjusted, no need to adjust; range refers to the pressure value of the pressure needed to press the tablets corresponds to the amplifier's measuring range, each range of pressure value corresponds to a certain weight of the amplifier. Each range of pressure value corresponds to a certain scale of the amplifier.