A figure of merit (FOM) is a
performance metric
A performance indicator or key performance indicator (KPI) is a type of performance measurement. KPIs evaluate the success of an organization or of a particular activity (such as projects, programs, products and other initiatives) in which it e ...
that characterizes the performance of a device, system, or method, relative to its alternatives.
Examples
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Absolute alcohol content per currency unit in an alcoholic beverage
*
Accuracy
Accuracy and precision are two measures of ''observational error''.
''Accuracy'' is how close a given set of measurements (observations or readings) are to their ''true value''.
''Precision'' is how close the measurements are to each other.
The ...
of a
rifle
A rifle is a long gun, long-barreled firearm designed for accurate shooting and higher stopping power, with a gun barrel, barrel that has a helical or spiralling pattern of grooves (rifling) cut into the bore wall. In keeping with their focus o ...
*Audio
amplifier figures of merit such as gain or efficiency
*Battery life of a
laptop computer
A laptop computer or notebook computer, also known as a laptop or notebook, is a small, portable personal computer (PC). Laptops typically have a Clamshell design, clamshell form factor (design), form factor with a flat-panel computer scree ...
Decoding Battery Life For Laptops
New York Times, June 25, 2009
*Calorie
The calorie is a unit of energy that originated from the caloric theory of heat. The large calorie, food calorie, dietary calorie, kilocalorie, or kilogram calorie is defined as the amount of heat needed to raise the temperature of one liter o ...
s per serving
*Clock rate
Clock rate or clock speed in computing typically refers to the frequency at which the clock generator of a processor can generate pulses used to synchronize the operations of its components. It is used as an indicator of the processor's s ...
of a CPU
A central processing unit (CPU), also called a central processor, main processor, or just processor, is the primary processor in a given computer. Its electronic circuitry executes instructions of a computer program, such as arithmetic, log ...
is often given as a figure of merit, but is of limited use in comparing between different architectures. FLOPS
Floating point operations per second (FLOPS, flops or flop/s) is a measure of computer performance in computing, useful in fields of scientific computations that require floating-point calculations.
For such cases, it is a more accurate measu ...
may be a better figure, though these too are not completely representative of the performance of a CPU.
*Contrast ratio
The contrast ratio (CR) is a property of a display system, defined as the ratio of the luminance of the brightest shade (white) to that of the darkest shade (black) that the system is capable of producing. A high contrast ratio is a desired aspec ...
of an LCD
A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers to display information. Liquid crystals do not em ...
*Frequency response
In signal processing and electronics, the frequency response of a system is the quantitative measure of the magnitude and Phase (waves), phase of the output as a function of input frequency. The frequency response is widely used in the design and ...
of a speaker
* Fill factor of a solar cell
A solar cell, also known as a photovoltaic cell (PV cell), is an electronic device that converts the energy of light directly into electricity by means of the photovoltaic effect.
* Resolution of the image sensor An image sensor or imager is a sensor that detects and conveys information used to form an image. It does so by converting the variable attenuation of light waves (as they refraction, pass through or reflection (physics), reflect off objects) into s ...
in a digital camera
A digital camera, also called a digicam, is a camera that captures photographs in Digital data storage, digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film or film stock. Dig ...
*Measure of the detection performance of a sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects o ...
system, defined as the propagation loss for which a 50% detection probability is achieved
*Noise figure
Noise figure (NF) and noise factor (''F'') are figures of merit that indicate degradation of the signal-to-noise ratio (SNR) that is caused by components in a signal chain. These figures of merit are used to evaluate the performance of an amplifie ...
of a radio receiver
*The thermoelectric figure of merit, ''zT'', a material constant proportional to the efficiency of a thermoelectric couple made with the material
*The figure of merit of digital-to-analog converter
In electronics, a digital-to-analog converter (DAC, D/A, D2A, or D-to-A) is a system that converts a digital signal into an analog signal. An analog-to-digital converter (ADC) performs the reverse function.
DACs are commonly used in musi ...
, calculated as (power dissipation)/(2ENOB × effective bandwidth) /Hz*Luminous efficacy
Luminous efficacy is a measure of how well a light source produces visible light. It is the ratio of luminous flux to power, measured in lumens per watt in the International System of Units (SI). Depending on context, the power can be either th ...
of lighting
Lighting or illumination is the deliberate use of light to achieve practical or aesthetic effects. Lighting includes the use of both artificial light sources like lamps and light fixtures, as well as natural illumination by capturing daylight. ...
*Profit
Profit may refer to:
Business and law
* Profit (accounting), the difference between the purchase price and the costs of bringing to market
* Profit (economics), normal profit and economic profit
* Profit (real property), a nonpossessory inter ...
of a company
A company, abbreviated as co., is a Legal personality, legal entity representing an association of legal people, whether Natural person, natural, Juridical person, juridical or a mixture of both, with a specific objective. Company members ...
*Residual noise remaining after compensation in an aeromagnetic survey
An aeromagnetic survey is a common type of geophysical survey carried out using a magnetometer aboard or towed behind an aircraft. The principle is similar to a magnetic survey carried out with a hand-held magnetometer, but allows much larger are ...
*Heat absorption and transfer quality for a solar cooker
A solar cooker is a device which uses the energy of direct sunlight to heat, cook or pasteurize drink and other food materials. Many solar cookers currently in use are relatively inexpensive, low-tech devices, although some are as powerful or as ...
Computational benchmarks are synthetic figures of merit that summarize the speed of algorithms or computers in performing various typical tasks.
References
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Engineering ratios