Gas Correction Factors for Ionization Vacuum Gauges
The values in the following table are the gas correction factors for various gases with respect to Nitrogen for both hot cathode and cold cathode ionization vacuum gauges.
In a gauge calibrated for Nitrogen, where the predominant gas being measured is other than Nitrogen, divide the actual gauge reading by the appropriate gas correction factor to get the corrected pressure value for the specific gas being measured.
| Gas |
Symbol |
Gas Correction Factor |
| Acetone | (CH3)2CO | 3.60 |
| Air | - - - | 1.00 |
| Ammonia | NH3 | 1.30 |
| Argon | Ar | 1.29 |
| Benzene | C6H6 | 5.90 |
| Bromine | Br2 | 3.80 |
| Bromomethane | CH3Br | 3.70 |
| Carbon Dioxide | CO2 | 1.42 |
| Carbon Disulfide | CS2 | 5.00 |
| Carbon Monoxide | CO | 1.05 |
| Carbon Tetrachloride | CCl4 | 6.00 |
| Chlorine | Cl2 | 0.68 |
| Deuterium | D2 | 0.35 |
| Helium | He | 0.18 |
| Hydrogen | H2 | 0.46 |
| Hydrogen Bromide | HBr | 2.00 |
| Hydrogen Chloride | HCl | 1.50 |
| Hydrogen Fluoride | HF | 1.40 |
| Isobutylene | C4H8 | 3.60 |
| Krypton | Kr | 1.94 |
| Methane | CH4 | 1.40 |
| Neon | Ne | 0.30 |
| Nitric Oxide | NO | 1.30 |
| Nitrogen | N2 | 1.00 |
| Nitrogen Oxide | NO | 1.16 |
| Nitrous Oxide | N2O | 1.50 |
| Oxygen | O2 | 1.01 |
| Phosphine | PH3 | 2.60 |
| Propane | C3H8 | 4.20 |
| Sulfur Dioxide | SO2 | 2.10 |
| Sulfur Hexafluoride | SF6 | 2.50 |
| Xenon | Xe | 2.87 |

Find gas correction factors for thermal-based mass flow controllers here.

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