| Abbreviation | Definition |
|---|---|
| RH | Relative Humidity |
| RHDA | Realtek High Definition Audio |
| RHEED | Reflection High-Energy Electron Diffraction |
| RHET | Resonant Hot-tunnelling Electron Transistor |
| RIBE | Reaction Ion Beam Etching |
| RIE | Reactive Ion Etching |
| RIEQ | Relay Interlocking EQuipment |
| RIM | Read-In Mode |
| RIMM | RAMBUS In-line Memory Module |
| RIO | Remote Input Output |
| RIP | Read, Interpolate, and Plot |
| RIPE | Robust Integrated Power Electronics |
| RIPS | Recorder Independent Power Supply |
| RIPS | Regulated Intelligent Power Supply |
| RIPT | Research Institute of Pulse Technique |
| RIR | Reflective Infrared sensor |
| RISC | Reduced Instruction Set Computer |
| RIST | Rule Induction and Statistical Testing |
| RIT | Receiver Incremental Tuning |
| RITD | Resonant Interband Tunnel Diode |