Liquid Filling 3. Use of Filling Machines ⚫ Volumetric filling is particularly appropriate for applications in the pharmaceutical industry where it is important that each container is accurately filled with a specific volume of product. ⚫ Constant level filling is used with see-through bottles in which it is important that all of the bottles in a display appear to be filled to the same level, although the bottles may not be exactly the same size and the volumes may be slightly different.Liquid Filling 3. Use of Filling Machines ⚫ Volumetric filling is particularly appropriate for applications in the pharmaceutical industry where it is important that each container is accurately filled with a specific volume of product. ⚫ Constant level filling is used with see-through bottles in which it is important that all of the bottles in a display appear to be filled to the same level, although the bottles may not be exactly the same size and the volumes may be slightly different