| Acronym | Meaning |
| TIME | Transferred Ionized Molten Energy Process (for Metal Arc Welding) |
| LDC | Less Developed Countries |
| AF | Audio Frequency |
| PACIMS | Passive Chem. Ionization Mass Spectrometry |
| DO | Diatomic Orbital |
| SEIRA | Surface-enhanced Infrared Absorption |
| AEAPS | Auger-electron Appearance-potential Spectroscopy |
| TSO | Time Sharing Option |
| CIPM | Comite International Des Poids Et Mesures |
| RAM | Reference-system Average Mayer-function (in Perturbation Theory) |