Analyze residual gases with corrected pressure estimates. Compare masses, abundance shares, and detection thresholds instantly. Export results, inspect trends, and document vacuum composition confidently.
Use chamber settings first. Then enter gas peaks below.
These values are included through the example loader button.
| Gas | Mass | Measured Current (A) | Sensitivity (A/Torr) | Fragmentation | Transmission |
|---|---|---|---|---|---|
| Hydrogen | 2 | 8.20E-10 | 8.50E-5 | 1.00 | 1.02 |
| Water Vapor | 18 | 2.10E-10 | 7.80E-5 | 0.95 | 0.99 |
| Nitrogen | 28 | 9.50E-11 | 7.20E-5 | 1.00 | 1.00 |
| Oxygen | 32 | 5.20E-11 | 7.10E-5 | 0.98 | 1.00 |
| Argon | 40 | 2.60E-11 | 6.90E-5 | 1.00 | 1.01 |
| Carbon Dioxide | 44 | 1.80E-11 | 6.40E-5 | 0.85 | 1.03 |
1. Net ion current: Inet = max(Imeasured - Ibaseline, 0)
2. Effective current: Ieffective = Inet / Gain
3. Corrected partial pressure: Pi = Ieffective / (Si × Fi × Ti)
4. Relative abundance: Ai(%) = Pi / ΣP × 100
5. Normalized pressure: Pnorm = Ptotal × Ai / 100
This workflow estimates gas contributions from corrected ion signals. Instrument calibrations, cracking patterns, and actual detector response may require lab-specific refinement.
It estimates corrected partial pressures for gases detected by a quadrupole residual gas analyzer. It also reports abundance share, normalized pressure, and a simple detection status for each listed mass peak.
Detector gain changes the relationship between measured current and true signal. Dividing by gain gives a cleaner estimate of effective current before converting that value into partial pressure.
Baseline noise represents background current not caused by the gas peak itself. Subtracting it prevents inflated pressure estimates when the measured signal is very weak.
Fragmentation accounts for cracking pattern effects. Transmission reflects mass-dependent instrument response. Together, they improve the raw signal correction and produce more realistic pressure estimates.
Normalized pressure redistributes the entered chamber pressure using each gas abundance percentage. It helps compare calculated species contributions against the total chamber reading.
No. This page is a practical estimation tool. Formal calibration, verified sensitivity constants, and instrument-specific response curves are still required for high-confidence laboratory reporting.
Differences usually come from incomplete gas selection, imperfect sensitivities, background drift, cracking overlaps, or real instrument bias. The coverage ratio highlights how closely the selected peaks explain the chamber reading.
The status compares each calculated partial pressure to the chosen detection limit. It classifies values as below limit, trace, moderate, or strong for faster review.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.