Determine the monitoring and measurement resources with the appropriate characteristics to ensure valid and reliable results of the conformity of the products or services. Demonstrate the client and legal requirements applicable to these resources, if any, were determined. Make the resources available, identified, used and maintained in an appropriate manner for the intended use. To the extent necessary, preventive maintenance activities are planned, curative interventions, verification or calibration instructions are given for their correct use and preservation and the qualification of the people who ensure intended and proper use. As evidence of the suitability for the purpose of the monitoring and measurement resources, keep records that demonstrates the suitability of the equipment to the intended purpose. Equipment must be identified with a unique reference, and with their state of fitness, for not be used inappropriately.