An accredited calibration laboratory must calculate and apply recall intervals for:

The correct answer is that an accredited calibration laboratory must calculate and apply recall intervals for its own equipment only. An accredited laboratory needs to establish internal procedures for ensuring that its equipment remains accurate and meets regulatory requirements. This involves determining appropriate calibration intervals based on factors such as usage, environmental conditions, and the type of measurements being taken.

While a laboratory certainly provides calibration services for client equipment, the responsibility for recall intervals primarily pertains to the laboratory's own measuring and test equipment, which directly impacts the quality and reliability of its calibration services. This focus ensures that the lab can maintain a high standard of accuracy and compliance.

Determining recall intervals for all industry-standard equipment or client equipment upon request does not fall under the laboratory's direct responsibility. Instead, these factors may vary with different clients or industries, making it impractical for a lab to set standard intervals universally. The laboratory's core responsibility is to ensure that its own equipment is calibrated and reliable, which is critical for providing accurate services to clients.