# Engineering

## Electrical element

An electrical element is a conceptual abstraction representing idealized electrical…

## Port (electric circuit theory)

In electrical circuit theory, a port is a pair of…

“No load voltage” is a common term used for unregulated…

## Ground or earth

In an electrical circuit there are always points with different…

## Second (unit of time)

The unit of time, the second, abbreviated s, was at…

## Metre (or meter)

The unit of length is the meter (or metre), defined…

## Worm gear

A worm gear is similar to a screw having single…

## Hypoid gear

Hypoid gears are similar to bevel gears, but the axes…

## Bevel gears

Bevel gears are used to connect shafts at any desired…

## Herringbone gear

Herringbone gears have two sets of helical teeth, one right-hand…

## Gear rack

The gear rack have the same sized and shaped teeth…

## Helical gear

Helical or “dry fixed” gear, is a type of gear…

## Spur gear

Spur gears, or straight-cut gears, are the simplest and the…

## Gear (cogwheel)

A gear (or cogwheel) it is the main element in…

## Influence quantities in measurements

In metrology, in cases where the environmental conditions of the…

## Measurement error

Measurement error is the difference between a measured value of…

## Measurement uncertainty

Measurement uncertainty is the degree of uncertainty with which the…

## Dynamic error

In metrology, dynamic errors are caused by dynamic influences acting…

## Static error

In metrology, static errors are those errors evaluated in static…

## Measurement chain

With measurement chain, we refer to the set of stages…

## Mobility error

In metrology, the mobility error is mainly due to the…

## Gross error

In metrology, gross errors are those attributable to inexperience or…

## Material science

Materials science allows to correlate the nature, disposition, and strength…

## Biomechanics

Biomechanics is the study of how the systems and structures…

## Bioinformatics

Bioinformatics is an interdisciplinary field of science that combines biology,…

## Biological engineering

Biological engineering, or bioengineering/bio-engineering, is the application of principles of biology…

## Buoyancy

Buoyancy or upthrust is an upward force exerted by a…

## Direct current (DC)

Direct current (DC) is electricity flowing in a constant direction,…

## Triboelectric nanogenerator (TENG)

Triboelectric nanogenerators (TENG) is an energy harvesting device that converts…

## Wear

Wear is the damaging, gradual removal or deformation of material…

## Electric resistance

The electrical resistance is the opposition to the motion of…

## Passive device

Components incapable of controlling current by means of another electrical…

## Active device

An active device is any type of circuit component with…

## Filter circuit

Circuits capable of selectively filtering one frequency or range of…

## Organic light-emitting diode (OLED)

OLED (Organic Light Emitting Diodes) is a light-emitting diode (LED),…

## Electric circuit

An electric circuit is an unbroken loop of conductive material…

## Piston

A piston is a component of reciprocating engines, reciprocating pumps,…

## Biogas

Biogas is a mixture of different gases produced by anaerobic…

## Biomaterial

A biomaterial is any substance that has been engineered to…

## Biotribology

Biotribology is the study of friction, wear and lubrication of…

## Biofluid mechanics

Biological fluid mechanics, or biofluid mechanics, is the study of…

## Kinesiology

Kinesiology (from the Greek κίνησις kínēsis, “movement” (itself from κινεῖν…

## Nuclear potential energy

Nuclear potential energy is the potential energy of the particles…

## Rigid body

A rigid body (also known as rigid object) is defined…

## Ultimate tensile strength (UTS)

Ultimate tensile strength (UTS), often shortened to tensile strength (TS),…

## Compression strength

Compressive strength or compression strength is the capacity of a…

## Shear strength

In engineering, shear strength is the strength of a material…

## Fracture toughness

Fracture toughness is a property which describes the ability of…

## Fracture

In metallurgy, the fracture is a sudden break of metal…

## Ductility

Ductility is a technological property of matter that indicates the…

## Indentation hardness

Indentation hardness tests are used in mechanical engineering to determine…

## Electrical impedance

Electrical impedance is a physical quantity that represents the opposition…

## Plasticity

Plasticity is the capacity to resist plastic deformation (dislocation movement…

## Viscoelasticity

Viscoelasticity is the study of materials which have a time-dependent…

## Piezoelectric transducer

The relationship between the mechanical stress applied to the crystal…

## Semiconductor

A semiconductor is a substance with an electrical conductivity between…

## Amorphous semiconductor

An amorphous semiconductor also called “thin film” is a non-crystalline…

## Ablation

Ablation is the removal of material from the surface of…

## Abrasive

An abrasive is any material (often a mineral) used to…

## Getter

The getter is an inert electrode, coated with magnesium or…

## Temperature

Temperature is a physical property of a material that gives…

## Calibration

Calibration is the procedure used to establish a relationship between…

## Repeatability

In metrology repeatability is a static characteristic of an instrument defined as…

## Stability

In metrology, stability is the ability of an instrument to…

## Drift

In metrology drift can be defined as the variation caused…

## Threshold of hearing

Sound level measurements in decibels are generally referenced to a…

In metrology, dead space or threshold is a static characteristic of…

## Resolution

In metrology the resolution of a measuring instrument is the…

## Range of interval (or span)

In metrology the range of the interval $$[a, b]$$ is the…

## Reproducibility

In metrology, the term “reproducibility,” when reported in instrument specifications,…

## Linearity

In metrology, linearity is actually a measure of nonlinearity of…

## Precision

In metrology, precision indicates the repeatability or reproducibility of an…

## Sensitivity

In metrology sensitivity of a measuring instrument is that metrological…

## Accuracy vs Precision

The difference between precision and accuracy needs to be understood…

## Accuracy

Accuracy is the degree of agreement of the measured dimension…

## Hysteresis

Hysteresis is a delay of the effect when the forces…

## Luminous intensity (candela)

The units of luminous intensity based on flame or incandescent…

## Measurement instrument

A device used for the measurement of a certain physical…

## Time

Time is an abstract entity (as well as a physical…

## Calorimetry

Calorimetry is used to measure the amount of thermal energy…

## Equipotential surface

An equipotential surface is therefore defined as the set of…

## Hertz

The hertz (symbol: Hz) is the derived unit of frequency…

## Voltage

The potential energy, stored in the form of an electric…

## Linear Variable Differential Transformer (LVDT)

A linear variable differential transformer (LVDT) is one of the…

## MEMS accelerometer

The accelerometers realized with MEMS technology (Micro-Electro-Mechanic System) are nothing…

## Laser accelerometer

The laser accelerometer is a particular type of the accelerometer…

## Piezoelectric accelerometer

The piezoelectric accelerometer uses, as a principle for detecting mass…

## Capacitive accelerometer

The capacitive accelerometer uses, as the operating principle for detecting…

## LVDT accelerometer

The LVDT accelerometer uses an LVDT (Linear Variable Differential Transformer)…

## Piezoresistive accelerometer

The piezoresistive accelerometer is a variant of the strain gauge…

## Strain gauge accelerometer

The strain gauge accelerometer uses the same principle of the…

## Apparent weight

Apparent weight is a property of objects that correspond to…

## Specific weight

The weight of a unit volume of a substance is…

## Weight

Weight is the force of gravity acting on an object.…

## Accelerometer

An accelerometer is a measuring instrument able of detecting and/or…

## Decibel

The decibel (symbol: dB) is a unit of measurement used…

## Parallam – Parallel strand lumber (PSL)

Parallam© is a composite material obtained by the union of…

## Tolerance

Tolerance means the limit or acceptable limits of the variations…

## Systematic error

Systematic errors are predictable and typically constant or proportional to…

## Random error

Random error is always present in a measurement. It is…

## Parallax

Parallax is a deceptive change in the relative position of…

Reading error is that what happens when evaluating the relative…

## Insertion error

The insertion error is caused by the presence of the…

## Rapidity error

The error of rapidity is that metrological quality of a…

## Error band

The range of maximum deviation of the transducer output from…

## Fidelity error

In Metrology, it is said that a measuring instrument is…

## Zero error

Zero error means the error that is made when long-term…

## Sensor

In Metrology, a sensor is a sensitive device placed in…

## Transducer

A transducer is a technological device capable of switching the…

## Flow rate

In metrology the term flow rate indicates the maximum value…

## Gravimeter

The gravimeter is a particular type of accelerometer specifically designed…

## Prandtl number

The Prandtl number (Pr) is a dimensionless number that expresses…

## Reynolds number

The Reynolds number is a dimensionless parameter that represents the…

## Rayleigh number

The Rayleigh number (Ra) is a dimensionless parameter that expresses…

## Grashof number

The Grashof number is a dimensionless parameter which, unlike the…

## Nusselt number

The Nusselt number (Nu) represents the ratio between the heat…

## Barograph

A barograph is an altimeter equipped with devices for recording…

## Barothermograph

A barothermograph consists of a barograph and a thermograph, which…

## Altimeter

An altimeter is a measuring instrument used to determine the…

## Thermograph

A thermograph is a measuring instrument capable of recording the…

## Barothermohygrograph

A barothermohygrograph consists of a barograph and a hygrograph, which…

## Hygrograph

A hygrograph is a measuring instrument consisting of an absorption…

## Bathythermograph

A bathythermograph is a measuring instrument used mainly in bathymetry,…

## Thermohygrograph

A thermohygrograph is a measuring instrument used in meteorology, consisting…

## Bolometer

The bolometer is a measuring instrument made by Langley Samuel…

## Boundary scan

The boundary scan (or JTAG) indicates a method of testing…

## Electric thermometer

Electric thermometers are temperature transducers that exploit the phenomena of…

## Resistance thermometer

Resistance thermometers are a type of electric thermometers, simple resistive…

## Thermistor (semiconductor thermometer)

Thermistors are electric thermometers made by sintering semiconductor powders such…

## Thermocouple

A thermocouple is a temperature transducer (electric thermometer) whose physical…

## Strain gauge (extensometer)

In Metrology, extensometry studies the measurement of the deformation of…

## Lubricant

A lubricant is an organic or synthetic substance (it can…

## Sensibility

In metrology, the sensitivity of a measuring instrument is a…

## Microelectromechanical systems (MEMS)

The MEMS technology (acronym of Micro Electro Mechanical Systems) is…

## Noise

In metrology, noise is defined as the set of random…

## Elastomer

Elastomer is defined as a macromolecular material (natural or synthetic…

## Thermoplastic elastomer

Thermoplastic elastomers (TPE), sometimes referred to as thermoplastic rubbers, are…

## International System of Units (SI)

The International System of Units universally abbreviated SI (from the…

## Energy

Energy is defined as a measurement of the ability to do work or to heat an…

## Non-renewable energy

Non-renewable energies are energy sources that tend to run out…

## Renewable energy

Renewable energy is a kind of energy from sources that…

## Energy harvesting

Energy harvesting (also known as power harvesting or energy scavenging or…

## True value

In metrology, the exact value of a variable is called…

## Gilsonite

The Gilsonite (also known as “uintahite,” “asphaltum” or asphaltite), named…

## Measurement

In metrology the term measurement is closely associated with all the…

## Scientific method

The scientific method is an investigative process for experimentation and…

## Scientific notation

In many disciplines of science and engineering, very large and…

## Absolute error

The absolute error is generally defined as the difference between…

## Length

The length, quantitatively and objectively, identifies a material body according…

## Uncertainty

In metrology, the estimation of the dispersion of the values…

## Measurand

A measurand is defined as a physical quantity to be measured (such as length,…

## Physical quantity

A physical quantity is defined as a physical property of…

## Quantity value

In metrology, the quantity value represents the number and the…

An adhesive is a substance that bonds two surfaces to…

## Boundary layer

A boundary layer is a very thin layer of viscous…

## Laminar flow

Laminar flow is non-turbulent flow in smooth parallel (non-intersecting) paths…

## Laminar-turbulent transitional flow

The process of a laminar fluid flow becoming turbulent is…

## Turbulence or turbulent flow

Turbulence (or turbulent flow) is a flow regime characterized by…

## Metrology

Metrology is the science of measurement, embracing both experimental and…

## Engineering

Engineering is a discipline dedicated to problem-solving with the use…

## Fluid flow

A fluid flow may be described in two different ways:…

## Fluid

In physics, a fluid is a substance that continually deforms…

## Fluid mechanics

Fluid mechanics is one of the oldest and broadest fields…

## Anelasticity

Anelasticity is a characteristic of viscoelastic materials that depends on…

## Dimensionless quantity

Some quantities are defined as the ratio of two quantities…

## Algorithm

An algorithm is a set of detailed instructions defining a…

## Cybernetics

Cybernetics is the science of the control, communication, and processing…