Industrial Terminology Glossary – O
Office of Weights and Measures (OWM)
Office at NIST that ensures consistency in any laws, regulations or standards regarding weights and measurements
Ohm
The SI unit of electrical resistance, equal to the amount of resistance in a circuit energized with one volt of potential difference and transmitting a current of one ampere.
An electrical measurement device designed for the precise assessment of electrical resistance within various materials. Read More…
Ohm’s Law
An equation that describes how current, resistance and voltage are related. I=E/R where R is resistance, I is current and E is voltage
An optical comparator, often referred to as a profile projector, is an instrument used in the inspection and measurement of manufactured components. It operates by leveraging optical techniques to project an enlarged and precise silhouette of the examined part onto a viewing screen. Read More…
Optical Flat
An optical-grade piece of glass lapped and polished to be extremely flat on one or both sides, usually within a few tens of nanometres (billionths of a meter). Used as a reference against which the flatness of an unknown surface may be compared.
Opto-Isolator
Also known as optical coupler, optocoupler and opto-isolator, a semiconductor device that uses a short optical transmission path to transfer an electrical signal between circuits or elements of a circuit, while keeping them electrically isolated from each other.
Original Equipment Manufacturer (OEM)
The original company who manufactured the equipment. Typically the equipment is used as parts in other equipment by other manufacturers and then resold
Oscilloscope
A device measures voltage as a function of time, allowing an AC current (via a special probe) or voltage to be displayed as an oscillating waveform.
Output
The signal produced by a device when an input is applied. Often, transducers and load cells output a voltage or current which can be measured by a meter and scaled with the circuitry in the indicator to provide a reading in the desired unit of measure.
Over Range
Exceeds the full scale reading but does not exceed maximum safe overload capacity.
Overload
The load beyond full-scale value that an instrument can withstand without damage or failure. Usually expressed as a percent of a full-scale value.
Overload Rating (Safe)
The maximum weight that can be put on a scale before it permanently alters performance of the scale.
Overload Rating (Ultimate)
The maximum weight that can be put on a scale before it is damaged structurally.
Overshoot
The ratio of the overtravel of the pointer beyond a new steady deflection to the change in steady deflection when a new constant value of the measured quantity is suddenly applied.