Alarm Limits for Gas Fired Engines
Engine manufacturers have recognized the advantages of oil analysis, and now produce bulletins on an annual basis which summarize oil analysis alarms. They are also very helpful for engine component metallurgy knowledge. These bulletins may be had by calling your local engine distributor, or by contacting the oil analysis laboratory.
Many gas fired engines have catalytic convertors which require a low ash/ashless detergent oil. Consult with the lubricant vendor to ensure compatibility with convertor systems.
Suggested condemnation limits for Gas Fired Engines
| Oil analysis test | Alarm limits | Further Action by Lab |
| Spectrochemical Analysis | 10 % increase over last sample | |
| RFS (Doublecheck) | 2:1 ratio or greater coarse to fine | Compare to trend, Ferrography |
| Viscosity | +20% or -10% of nominal ISO grade | |
| Oxidation | 0.2 Abs/0.1 mm over last sample max 1.00 | TAN |
| Nitration | 0.2 Abs/0.1 mm over last sample max 1.00 | TAN |
| TBN | Half of new oil value, or equal to TAN 1.0 mg KOH/g min value |

