To avoid any misunderstanding about your request and our services, we provide the definitions from the standard reference for the metrological maintenance of measuring instruments (ISO 17025) :

• Calibration: it the establishment of the relationship between the values indicated by a measuring instrument and the corresponding values of quantities provided by a reference. The calibration is used to estimate indications errors of the instrument. The correction is shown as a calibration curve.

• Ajustment : the ajustment is made by the manufacturer of the instrument or by a specialized laboratory. It involves devices that are normally not accessibles by the user, and allows to bring an instrument in conformity with it use. It is often linked with the calibration. 

• Verification : it is the confirmation by examination and provision of objective evidences that specified requirements have been met or not. Concretely, it is verified by comparizon to a reference  that a measuring instrument is set within the required tolerances.