what is potentiometer (pots) potentiometer transducers or s

BRIGHT HUB ENGINEERING

Home > Mechanical Engineering > HVAC / HVACR

Civil Engineering Electrical Engineering Marine Engineering Mechanical Engineering

Leave a commentWhat is Potentiometer? Potentiometer Used as theTransducer or Sensor

written by: Haresh Khemani edited by: Lamar Stonecypher updated: 9/1/2009

Potentiometer is one of most commonly used devise for measurement of the displacement of the body. This articledescribes what potentiometer is and how it can be used as the transducer.

Principle of Working of Potentiometers

The potentiometer is also called as pots and it one ofthe most commonly used devise for measuring thedisplacement of the body. The potentiometer is theelectrical type of transducer or sensor and it is ofresistive type because it works on the principle ofchange of resistance of the wire with its length. Theresistance of the wire is directly proportional to thelength of the wire, thus as the length of the wirechanges the resistance of the wire also changes.

What is Potentiometer?

The potentiometer is an electric circuit in which theresistance can be changed manually by the slidingcontacts. The typical potentiometer is shown in thefigure below. Here the voltage Vs is applied across thetwo points of the wire A and B. C is the variable contactpoint between A and B and its position can be changedby the sliding contact. The voltage Vo is measuredbetween the points A and C.

As per the resistance law of the conductor, theresistance of the conductor AC changes as the lengthof the wire AC changes. Accordingly the output voltageVo between A and C also changes. The point C is theslider whose position is changed by the operator or bythe motion of the body whose displacement is to be

measured. The relationship between the length of the conductors and the voltage across them can be expressedas:

Vo/Vs = AC/AB

Potentiometer Sensors Transducer Proximity

CustomOptical

Components

What is Potentiometer (Pots)? Potentiometer Transducers or Sensors. 2/17/2015

http://www.brighthubengineering.com/hvac/47389-what-is-potentiometer-potentiometer-used-as-the-transducer-or-sensor/#imgn_0 1 / 5

How Potentiometer is used as the Transducer

There are number of applications of the potentiometer or pots, of these one of the most common applications is themeasurement of displacement. To measure the displacement of the body, this body, which is moving, is connectedto the sliding element of the potentiometer.

As the body moves, the position of the slider located on the potentiometer also changes so the resistance betweenthe fixed point and the slider changes. Due to this the voltage Vo across these points also changes. The change involtage or the resistance is proportional to the change in the displacement of the body. Thus the voltage changeindicates the displacement of the body. The potentiometer can be used for the measurement of translational aswell as well rotational displacement. Since these potentiometers work on the principle of resistance, they are alsocalled as the resistive potentiometers.

Important Performance Parameters of the Potentiometers

1) Potentiometer resolution: Though the resistance of the conductor is proportional to its length, when the slidermoves over the wire the change in the resistance is not continuous function of the contact movement. The smallestincrement of the slider that can be recorded across the whole length of the potentiometer is called as the resolution.If resistance winding is used in the potentiometer, its limiting resolution is measured as the reciprocal of thenumber of turns of the coil. The lower the length that can be recorded higher is the resolution of the potentiometer.

2) Potentiometer linearity: Ideally the resistance measured between the fixed point and the slider point is linearfunction of the contractor position relative to that end. In actual cases the change in resistance and the distancebetween the fixed and the moving point is never linear. The maximum allowable deviation between change inresistance and the linear position of the slider is called as the linearity tolerance.

Reference

1) Book: Mechanical Measurements by Thomas G. Beckwith and N. Lewis Buck

2) Book: Measurement and Instrumentation Principles by Alan S Morris.

Image Courtesy

1) Book: Measurement and Instrumentation Principles by Alan S Morris.

WHAT IS POTENTIOMETER?This is the series of articles that describes what is potentiometer, also called as pots, its types and it can be usedas the transducer.

What is Potentiometer? Potentiometer Used as the Transducer or Sensor

Types of Potentiometers

WE ALSO RECOMMEND...What is a Thermocouple & How Does it Work?

What's the Difference Between AC and DC Electric Shocks?



What You Need to Know to Make Our Electronic Circuits at Bright Hub Engineering

Pressure Measurement: Pressure Measurement Devices

Causes and of Rust and Protection Through Galvanization

Knight OpticalLTD

Quality Optics, largequantities in stock. Fast

& Efficient Service.

2012 Bright Hub Inc. All Rights Reserved

Tweets

Share

TweetTweet 1

About BH EngineeringContact UsAdvertise With UsRSS

Terms of UsePrivacy PolicyCopyright Policy



Civil Engineering Electrical Engineering Marine Engineering Mechanical Engineering

Site Links

Additional Info

SUBSCRIBE & FOLLOW:

RELATED TOPICS:CAD Reviews & TipsEnergy/ Power PlantsFluid Mechanics / HydraulicsHVAC / HVACRMachine DesignManufacturing TechnologyRoboticsThermodynamics

More Info

SIGNUP FOR EMAILSClick here to signup for our newsletter



copyright 2015 brighthubengineering.com privacy policy



BRIGHT HUB ENGINEERINGWhat is Potentiometer? Potentiometer Used as the Transducer or SensorPrinciple of Working of PotentiometersWhat is Potentiometer?How Potentiometer is used as the TransducerImportant Performance Parameters of the PotentiometersReferenceImage CourtesyWHAT IS POTENTIOMETER?

WE ALSO RECOMMEND...ShareAdditional InfoSUBSCRIBE & FOLLOW:RELATED TOPICS:More InfoSite Links

what is potentiometer (pots) potentiometer transducers or s

Documents