§ 1065.750 Analytical gases.
Analytical gases must meet the accuracy and purity specifications of this section, unless you can show that other specifications would not affect your ability to show that you comply with all applicable emission standards.
(a) Subparts C, D, F, and J of this part refer to the following gas specifications:
(1) Use purified gases to zero measurement instruments and to blend with calibration gases. Use gases with contamination no higher than the highest of the following values in the gas cylinder or at the outlet of a zero-gas generator:
(i) 2% contamination, measured relative to the flow-weighted mean concentration expected at the standard. For example, if you would expect a flow-weighted CO concentration of 100.0 µmol/mol, then you would be allowed to use a zero gas with CO contamination less than or equal to 2.000 µmol/mol.
(ii) Contamination as specified in the following table:
Table 1 of § 1065.750—General Specifications for Purified Gases a
| Constituent | Purified air | Purified N2 |
|---|---|---|
| THC (C1-equivalent) | ≤0.05 µmol/mol | ≤0.05 µmol/mol. |
| CO | ≤1 µmol/mol | ≤1 µmol/mol. |
| CO2 | ≤10 µmol/mol | ≤10 µmol/mol. |
| O2 | 0.205 to 0.215 mol/mol | ≤2 µmol/mol. |
| NOX | ≤0.02 µmol/mol | ≤0.02 µmol/mol. |
| N2O b | ≤0.02 µmol/mol | ≤0.02 µmol/mol. |
a We do not require these levels of purity to be NIST-traceable.
b The N2O limit applies only if the standard-setting part requires you to report N2O or certify to an N2O standard.
(2) Use the following gases with a FID analyzer: