The invention relates to a cell for testing geomaterials on cylindrical specimens, of rock, ground or materials manufactured on sampling sites, including at least one piston for subjecting a specimen to a stress directed along the longitudinal axis of the specimen. A personal electronic device such as a cameral telephone can have two cameras that have overlapping fields of view. The controller is programmed to formulate a serving which best matches the customised serving selected by the customer within constraints set by the programming taking into account the inventory of ingredients and the health profile of the customer.