# Characteristics of Sensors

Sensors are characterized depending on the value of some of the parameters. Important

Closely Related Articles
Transducer | Types of TransducerResistance Temperature Detector or RTD | Construction and Working PrincipleThermistor Thermometer | Thermistor Temperature Sensor | Construction and Principle Thermistor Definition Properties Construction Characteristics and Applications Bimetallic Strip ThermometerThermocouple Temperature MeasurementTemperature TransducersRadiation Pyrometer | Types Working PrincipleOptical Pyrometer | Construction and Working PrinciplePiezoelectric TransducerStrain GaugeInductive TransducersLinear Variable Differential Transformer LVDTOscillator TransducerHartley OscillatorColpitts OscillatorClapp OscillatorRC Phase Shift OscillatorWien Bridge OscillatorGunn OscillatorCrystal OscillatorMonostable MultivibratorBistable MultivibratorWhat is an Oscillator?Astable MultivibratorVoltage Controlled Oscillator | VCOMore Related Articles
Digital PotentiometersWheatstone Bridge Circuit Theory and PrincipleKelvin Bridge Circuit | Kelvin Double BridgeMaxwell Bridge Inductance Capacitance BridgeAnderson′s Bridge | Advantages Disadvantages of Anderson′s BridgeHay′s Bridge Circuit Theory Phasor Diagram Advantages ApplicationsOwens Bridge Circuit and AdvantagesSchering Bridge Measurement of Capacitance using Schering BridgeDe Sauty BridgeHeaviside Bridge CircuitBlavier Test | Murray Loop Test | Varley Loop Test | Fisher Loop TestCathode Ray Oscilloscope | CROLissajous Patterns of CRO or Cathode Ray OscilloscopeFrequency Limitation of an OscilloscopeSignal GeneratorMeasurement of Voltage Current and Frequency by OscilloscopeDigital Storage OscilloscopeDouble Beam OscilloscopeSampling OscilloscopeSensor | Types of SensorTemperature Sensor Temperature Measurement | Types of Temperature SensorVoltage SensorMeasurement of ResistanceElectrical Measuring Instruments | Types Accuracy Precision Resolution SpeedErrors in Measurement | Classification of ErrorsPermanent Magnet Moving Coil Instrument or PMMC InstrumentMoving Iron InstrumentElectrostatic Type Instruments Construction Principle Torque EquationRectifier Type Instrument | Construction Principle of OperationThermocouple type Instruments Construction Principle of OperationProtection of MetersAir MeterWater MeterDigital Frequency MeterOhmmeter Working Principle of OhmmeterPotentiometer Working Principle of PotentiometerInduction Type MetersWhat is Low Power Factor Wattmeter ?Energy Meter with Lag Adjustment DevicesElectrodynamometer Type WattmeterMeasurement of Three Phase PowerVarmeter | Single Phase and Polyphase VarmeterMegger | Working Principle Types History Uses of MeggerWeston Type Frequency MeterPower Factor Meters | Electrodynamometer Type Power Factor MeterPhase Sequence IndicatorAmmeter Working Principle and Types of AmmeterDigital MultimeterInsulation Resistance Test and Polarization Index TestTan Delta Test |Loss Angle Test | Dissipation Factor TestElectronic DC VoltmeterWorking Principle of Voltmeter and Types of VoltmeterDigital Voltmeters Working Principle of Digital VoltmeterMeasurement of Electrical EnergyEnergy Meter TestingAC PotentiometerConstruction of AC Energy MeterWatt Hour MeterCapacitance MeterVector Impedance MeterHow to Use a Digital Multimeter?Flow MeasurementFlow MeterNew Articles
Electrical and Electronics Engineering BooksWater MeterAir MeterDigital PotentiometersBasic Construction of Wind Turbine**characteristics of sensors**and transducers are listed below:- Input characteristics
- Transfer characteristics
- Output characteristics

## Input Characteristics of Sensors

- Range: It is the minimum and maximum value of physical variable that the sensor can sense or measure. For example, a Resistance Temperature Detector (RTD) for the measurement of temperature has a range of -200 to 800
^{o}C. - Span: It is the difference between the maximum and minimum values of input. In above example, the span of RTD is 800 - (-200) = 1000
^{o}C. - Accuracy: The error in measurement is specified in terms of accuracy. It is defined as the difference between measured value and true value. It is defined in terms of % of full scale or % of reading.
X
_{t}is calculated by taking mean of infinite number of measurements. - Precision: It is defined as the closeness among a set of values. It is different from accuracy. Let X
_{t}be the true value of the variable X and a random experiment measures X_{1}, X_{2}, …. X_{i}as the value of X. We will say our measurements X_{1}, X_{2},… X_{i}are precise when they are very near to each other but not necessarily close to true value X_{t}. However, if we say X_{1}, X_{2},… X_{i}are accurate, it means that they are close to true value X_{t}and hence they are also close to each other. Hence accurate measurements are always precise. - Sensitivity: It is the ratio of change in output to change in input. If Y be the output quantity in response to input X, then sensitivity S can be expressed as
- Linearity: Linearity is the maximum deviation between the measured values of a sensor from ideal curve.
- Hysteresis: It is the difference in output when input is varied in two ways- increasing and decreasing.
- Resolution: It is the minimum change in input that can be sensed by the sensor.
- Reproducibility: It is defined as the ability of sensor to produce the same output when same input is applied.
- Repeatability: It is defined as the ability of sensor to produce the same output every time when the same input is applied and all the physical and measurement conditions kept the same including the operator, instrument, ambient conditions etc.
- Response time: It is generally expressed as the time at which the output reaches a certain percentage (for instance, 95 %) of its final value, in response to a step change of the input.