The flow calibrators are equipment that allows to verify the state of sampling pumps or samplers that work by means of a suction pump which must work at a volumetric flow. The flow calibrators are patterns that allow to calibrate the flows to which a suction pump mechanism works and in the end they are the elements that give us the real flow to which the equipment is operating. These calibrators are used with sampling pumps, environmental samplers or any other instrument that has an internal pump that operates in a determined volumetric flow which must be verified in order to guarantee the correct operation of said equipment.