Section 868.6400 - Calibration gas(a)Identification. A calibration gas is a device consisting of a container of gas of known concentration intended to calibrate medical gas concentration measurement devices.(b)Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 868.9 .47 FR 31142, July 16, 1982, as amended at 61 FR 1121, Jan. 16, 1996; 66 FR 38796, July 25, 2001