Learnto usean impedanceMeter!Basic measurement techniques
Overview
Impedance metersare used to measure the impedancealso known as resistance, toAC.(AC). Thispage gives a comprehensiveintroduction to basic knowledge aboutimpedance and methods of measuringimpedance, and howto use an impedance meter.
What isthe definition of impedance?
Let’s begin by delving into the concept ofimpedance. Insimple words, impedanceisthe term used to defineresistance to theflowofone’sAC current.
When you connect a electricproduct, motor,orany otherequipment toanyACelectric power supply,the current flowsthrough thedevice’s circuitry. Impedance iscalculatedby dividing the voltage inthe circuit withits current. Insimple terms, it canbedescribed as restricting theflow of currentwithintheAC circuit. Impedance isrepresented byitssymbol “Z” and measured inOhms(O) that is the sameinstrument used to measureDC resistance. Thegreater the impedance,themore resistance there isto thecurrent flow.
What is the measurement of impedance?
Because impedance is nota visible phenomenon, it’simportant to have a measuringinstrumentto measureit. Instrumentsthat can measureimpedance are impedance meters,LCR meters as well as impedance analyzer. There area number ofmethods through which impedance maybe measured.
Bridge method
Thismethod employsan electronic bridge circuit to determineanunidentifiedresistance. It requiresthat balance adjustmentbedone using a galvanometer.Although this method providesthe greatest degree of accuracy(about 0.1 percent) It’s not the best suitedto high-speed measurement.
I-V method
This methodcalculates the impedance by measuringthe voltagesacross a currentdetector and an unknownimpedance. Itis also possiblefor measuringthose sampleswith a grounded.When the impedance grows,thetechnique becomes increasingly susceptibletoeffects caused bythevoltage meter.
The method of RF I.V
This method followsthe sameprinciple of measurementlike the I-V method. Itallows high-frequency impedance measurementthrough a circuit thatmatches the characteristic impedancethe high-frequency coaxial cable as well asan high-frequency coaxial connector.It’s difficult to use thismethod to measure widebands becausethemeasurement frequency bandislimitedthrough the tests head’s transistor.
Automatically balancedbridge system
The method used here is based on thefundamental measurement concept asusing the bridge technique. Itcoversan entire frequency range(1from mHz up to 100 MHz).However, that coveragedoes not extend to the higherfrequencies.A large number ofLCR metersemploy this technique.
Each impedance analyzer method offers its ownbenefits and disadvantages, and soyou’ll need to definethe kind of impedancesyou’ll need to gaugeprior to choosing the appropriatemethod to use.
Utilizing an impedance tester
The methodused to measure the impedancewill depend on the measurement instrumentutilized.For instance, Hioki’s LCRMeter IM3523can measure impedancewith a high degree ofaccuracy over a wide rangeoffrequency settings.
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40 Hz measurement
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200Hz measurement
Apart from normal measurement This instrument can be used tocontinuously and quickly monitor differentparametersin differentconditions(measurement frequency andsignal strength).
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C-D+ESR Measurement of Capacitors
impedance analyzeralso allows for the saving ofup to 60 setsin measurement conditionsin addition to up to128corrections values for open/short correctionandcable length correction.It is possible to load groups of settingsquickly loaded at onceto enhanceefficiency.
Additionally, the instrument’s externalcontrol terminalscan be used to createautomatedtesting lines quicker.
Impedance measurement is unstable.measurement
The measurement methodemployed, impedance meterswill return different valuesevery time a measurement istaken. Ifyour impedance meter’smeasured values are not stable and remain stable, you should check these:
Parasitic components of the components beingmeasured
Alongside the designvaluesfor resistance and reactance,componentshave parasitic components thatcreate a range ofvalues.Even differences in thelength ofthe lead that is connectedtothe components and thedistance between themcouldresult in measured values varying.
Measurementenvironmental
Impedance measurement results aredependent on a variety ofconditions, includingthat of the temperatures notonlyresistors,but also inductors and capacitors as well asprobe capacitance as well as stray capacitance.
Thisis why it is necessary to take stepsthat ensure a consistentmeasurement environment and averaging multiplemeasurements instead ofusing a singlemeasurement tocalculatetheamount.
DC bias
DC biasor DC isvery smallamount of voltage present in measuringdevicesand circuits.For example, it occurswhen the wire and probearemade from different components. Theresultant force of thermal electromotiveproducesDC bias.
Summary
Impedance determines the degree of resistance toan AC current. Itsmeasurement requiresa special instrument.Since there’s a myriadofmethods for measuring that you can choose from, it is important to selectthebest one based onyour requirements and each technique’sadvantages anddisadvantages.
Impedance measurement is verydelicate and prone to variabilitybecause of factors likethe measurement’s environment, frequency, andDC bias. Thismakes it necessary to performsteps such as averaging multiplemeasurements.
Applications
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Impedance measurement for Smart Keys/Immobilizers antennas
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MLCC
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Conductive polymer capacitors
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Tantalum capacitors
How to Use
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LCRMeasurement of meter principles
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How to Use an LCR Meter: Basic Knowledge
