U.S. Code of Federal Regulations

Regulations most recently checked for updates: Oct 07, 2025

§ 868.1640 - Helium gas analyzer.

(a) Identification. A helium gas analyzer is a device intended to measure the concentration of helium in a gas mixture during pulmonary function testing. The device may use techniques such as thermal conductivity, gas chromatography, or mass spectrometry.

(b) Classification. Class II (performance standards).