Engineering Glossary: I
57 definitions in plain language.
57 terms beginning with I. Use the filter to narrow the list, or the letters to jump to another part of the glossary.
57 terms
- I2C #
- A two-wire serial bus that connects many devices, each with an address. Programming, data and computing
- Ideal gas #
- A gas whose pressure, volume and temperature follow P V = n R T exactly. Fluids, heat and thermodynamics Read more: Ideal Gases and Processes
- IEC #
- International Electrotechnical Commission, which publishes standards for electrical and electronic technology. Math, units, quality and workshop
- IEC 61131-3 #
- The international standard that defines the five PLC programming languages. Automation, controls and robotics
- IEEE #
- Institute of Electrical and Electronics Engineers, a professional body that publishes standards and papers. Math, units, quality and workshop
- Impedance #
- The total opposition of a circuit to alternating current, combining resistance and reactance, in ohms. Electrical power and machines
- Impedance matching #
- Making a source and load impedance equal, or a transmission line terminated in its own impedance, to avoid reflections. Electronics
- Impulse #
- Force multiplied by the time it acts; it equals the change in momentum. Mechanical design and mechanics
- Inductance #
- The property of a coil that opposes changes of current, in henries. Electronics
- Induction hardening #
- Hardening the surface of a part by heating it with an induction coil and quenching it. Materials, manufacturing and measurement
- Induction motor #
- An AC motor in which the rotor current is induced by the stator's rotating field; simple, rugged and the most common industrial motor. Electrical power and machines Read more: Induction Motors and Drives
- Inductive reactance #
- The reactance of an inductor: 2 π f L, rising with frequency. Electrical power and machines
- Inductive sensor #
- A proximity sensor that detects metal objects by the change in a magnetic field. Automation, controls and robotics
- Inductor #
- A component that stores energy in a magnetic field and opposes changes of current. Electronics Read more: Inductors, Transformers and Relays
- Industrial Ethernet #
- Ethernet adapted for factory use, with protocols such as EtherNet/IP, PROFINET and EtherCAT. Automation, controls and robotics
- Industrial IoT #
- Connecting industrial machines to networks and the cloud to collect and use data. Automation, controls and robotics
- Industrial network #
- A communication network that links PLCs, drives, sensors and computers in a plant. Automation, controls and robotics Read more: Industrial Communication
- Inelastic collision #
- A collision in which some kinetic energy is lost, usually as heat and deformation. Math, units, quality and workshop
- Inertia #
- The tendency of a body to resist a change in its motion. Mechanical design and mechanics
- Inertia ratio #
- The load inertia divided by the motor inertia; a lower ratio gives better servo control. Automation, controls and robotics
- Infill #
- The internal pattern of a 3D-printed part, set by a percentage that trades strength against weight and time. Materials, manufacturing and measurement
- Injection molding #
- Making plastic parts by forcing molten plastic into a mold under pressure. Materials, manufacturing and measurement Read more: Injection Molding and Plastics Processing
- Inspection #
- Measuring or testing parts to check that they meet the specification. Materials, manufacturing and measurement
- Instrumentation amplifier #
- A precision amplifier for small differential signals, with high input impedance and common-mode rejection. Electronics
- Insulation #
- Material that slows heat flow, usually by trapping air in small cells. Fluids, heat and thermodynamics
- Insulation resistance #
- The resistance of the insulation between conductors or to earth, measured with a megohmmeter. Electrical power and machines
- Insulator #
- A material that does not carry current, such as rubber or plastic. Electrical power and machines
- Integer #
- A whole number without a fractional part. Programming, data and computing
- Integral #
- The accumulated total of a function over an interval; the area under its graph. Math, units, quality and workshop
- Integral action #
- The part of a PID output that adds up the error over time, removing steady-state error. Automation, controls and robotics
- Integral windup #
- The build-up of the integral term while an output is saturated, which causes large overshoot afterwards. Automation, controls and robotics
- Integrated circuit #
- A complete circuit built on a small piece of semiconductor. Also called an IC or chip. Electronics
- Interest rate #
- The yearly percentage charged or earned on money. Math, units, quality and workshop
- Interference #
- The amount by which a shaft is larger than the hole it is pressed into. Mechanical design and mechanics
- Interference fit #
- A fit in which the shaft is always larger than the hole so the parts must be pressed or shrunk together. Materials, manufacturing and measurement
- Interlock #
- A control that prevents an action unless a safe condition exists. Automation, controls and robotics
- Internal energy #
- The total energy stored within a substance as molecular motion and bonds. Fluids, heat and thermodynamics
- Internal resistance #
- The resistance inside a battery or cell that causes its voltage to drop under load. Electrical power and machines
- Interpolation #
- Estimating a value between known data points. Programming, data and computing
- Interpreter #
- A program that executes source code directly, line by line. Programming, data and computing
- Interrupt #
- A signal that makes a processor pause its current task and run a short handler routine. Programming, data and computing
- Interrupting rating #
- The highest fault current that a breaker or fuse can safely open. Electrical power and machines
- Interrupt service routine #
- The short code that runs when an interrupt happens. Programming, data and computing
- Inverse kinematics #
- Finding the joint angles that put a robot tool at a given position. Automation, controls and robotics
- Inverter #
- A device that converts direct current into alternating current. Electrical power and machines
- Investment casting #
- Casting in a ceramic mold formed around a wax pattern that is melted out; gives fine detail. Also called lost-wax casting. Materials, manufacturing and measurement
- Involute #
- The curve traced by the end of a string unwound from a circle, used for the shape of gear teeth. Mechanical design and mechanics
- IP address #
- A number that identifies a device on a network, such as 192.168.1.10. Automation, controls and robotics Read more: IP and Subnet Calculator
- IP rating #
- A code that states how well an enclosure keeps out solids and water. Electrical power and machines Read more: IP Ratings Explained
- ISO #
- International Organization for Standardization, which publishes international standards. Math, units, quality and workshop
- ISO 9001 #
- An international standard for quality management systems. Math, units, quality and workshop
- Isobaric process #
- A process at constant pressure. Fluids, heat and thermodynamics
- Isochoric process #
- A process at constant volume. Fluids, heat and thermodynamics
- Isolation #
- Separating two circuits so that no direct electrical path exists between them. Electronics
- Isothermal process #
- A process at constant temperature. Fluids, heat and thermodynamics
- Iteration #
- One round of design, build and test in a repeated development cycle. Math, units, quality and workshop
- IT grade #
- International tolerance grade: a number that sets the width of the tolerance zone for a given size, for example IT7. Materials, manufacturing and measurement