40 CFR 1065.255: H2 measurement devices.

(a) Component requirements. We recommend that you use an analyzer that meets the specifications in § 1065.205. Note that your system must meet the linearity verification in § 1065.307.

(b) Instrument types. You may use any of the following analyzers to measure H2:

(1) Magnetic sector mass spectrometer.

(2) Raman spectrometer.

(c) Interference verification. Certain compounds can positively interfere with magnetic sector mass spectroscopy and raman spectroscopy by causing a response similar to H2. Use good engineering judgment to determine interference species when performing interference verification. In the case of raman spectroscopy, determine interference species that are appropriate for each H2 infrared absorption band, or you may identify the interference species based on the instrument manufacturer's recommendations.