When can a laboratory place calibration interval recall dates on a certificate?

A laboratory can place calibration interval recall dates on a certificate when it has received explicit permission from the customer. This practice ensures that the customer is aware of the calibration schedule and acknowledges it, which fosters transparency and clarity regarding the calibration process. By obtaining consent from the customer first, the laboratory also demonstrates its commitment to customer service and compliance with any applicable regulatory or industry standards.

While the other options present different scenarios, they do not properly emphasize the importance of obtaining customer validation for such actions. Automatically placing recall dates without consent could lead to misunderstandings or disputes about the calibration schedule. Similarly, limiting the practice to only situations where the customer specifically requests the dates does not reflect proactive service, as it could be beneficial for laboratories to offer this information as part of standard procedures if approved by the customer. Lastly, placing recall dates only after the first calibration is completed overlooks the significance of having an agreed-upon schedule in advance, which can help in maintaining equipment reliability and performance.