Engineering Glossary: O
26 definitions in plain language.
26 terms beginning with O. Use the filter to narrow the list, or the letters to jump to another part of the glossary.
26 terms
- Offset voltage #
- The small input voltage difference that an amplifier needs to give zero output. Electronics
- Ohm #
- The SI unit of resistance: one volt per ampere. Electrical power and machines
- Ohm's law #
- Voltage equals current times resistance: V = I R. Electrical power and machines
- OPC UA #
- An open standard for secure data exchange between industrial devices and software. Automation, controls and robotics
- Open collector #
- An output that can pull a line low but not drive it high, needing a pull-up resistor. Electronics
- Open-loop control #
- Control that does not use feedback; the controller sends a command without checking the result. Automation, controls and robotics
- Open source #
- Software whose source code is freely available to use, study and change. Programming, data and computing
- Operating point #
- The flow and head where the pump curve crosses the system curve. Fluids, heat and thermodynamics
- Operating system #
- The software that manages a computer's hardware and runs programs. Programming, data and computing
- Operational amplifier #
- A high-gain voltage amplifier with differential inputs, used with feedback to build many circuits. Also called an op-amp. Electronics Read more: Op-amps and Integrated Circuits
- Optocoupler #
- A device that passes a signal between circuits using light, giving electrical isolation. Also called an optoisolator. Electronics
- Order of magnitude #
- A rough size of a number expressed as a power of ten. Math, units, quality and workshop
- Orifice plate #
- A plate with a hole placed in a pipe; the pressure drop across it measures flow. Fluids, heat and thermodynamics Read more: Flow Measurement
- O-ring #
- A rubber ring of round cross-section that seals by being squeezed in a groove. Math, units, quality and workshop Read more: O-Ring Cross-Sections and Groove Depths
- Oscilloscope #
- An instrument that displays how a voltage changes over time. Electronics Read more: Design, Testing and Troubleshooting
- OSHA #
- The US Occupational Safety and Health Administration. Math, units, quality and workshop
- Otto cycle #
- The idealized cycle of a spark-ignition engine. Fluids, heat and thermodynamics
- Outlier #
- A data point that lies far from the others and may be an error or a real extreme event. Programming, data and computing
- Overcurrent #
- Current above the rating of a conductor or equipment, caused by an overload or short circuit. Electrical power and machines
- Overfitting #
- When a model learns the noise in the training data and does poorly on new data. Programming, data and computing
- Overflow #
- A result too large to fit in the data type that holds it. Programming, data and computing
- Overhang #
- Part of a 3D print that extends beyond the layer below and may need support. Materials, manufacturing and measurement
- Overload #
- A current above the rated value that lasts long enough to heat a conductor or motor dangerously. Electrical power and machines
- Overshoot #
- The amount by which a signal goes past its final value before settling. Electronics
- Overshoot (control) #
- How far the response goes past the setpoint, as a percentage. Automation, controls and robotics
- Over-the-air update #
- Updating a device's firmware through a wireless link. Also called OTA. Programming, data and computing