# Metrology

Metrology is the science of measurement, embracing both experimental and theoretical determinations at any level of uncertainty in any field of science and technology.

## 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…

## 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…

## Piezoelectric transducer

The relationship between the mechanical stress applied to the crystal…

## 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…

## 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…

## 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…

## Gravimeter

The gravimeter is a particular type of accelerometer specifically designed…

## 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…

## 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…

## Sensibility

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

## Noise

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

## International System of Units (SI)

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

## True value

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

## Measurement

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

## 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…