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How Much You Need To Expect You’ll Pay For A Good impedance analyzer

Eugene Hill

Learnhow to usean impedancemeasurement instrument!Basic measurement methods

Overview

Impedance metersare used to measure the impedancealso known as resistance, toanAC.(AC). Thispage provides a detailedreview of the basics ofimpedance measurement, methods to measureimpedance and the best wayyou can use an impedance measurer.

What isimpedance?

Let’s start by definingimpedance. Insimple terms, itisa quantity that expressesresistance to thecurrentthroughone’sAC current.

When you connect an electricaldevice, motor,orany otherdevice toanyACelectric power supply,electricity will flowthrough thedevice’s circuitry. Impedance isdeterminedthrough the division of the voltage inthe circuit byits current. Insimple terms, it canbedefined as limiting theflow of currentintheAC circuit. Impedance isindicated withitssymbol “Z” and measured inohms(O) this is the exactunit that measuresDC resistance. Thegreater the impedance,themore resistance there isto thecurrent flow.

How is impedance measured?

Since impedance isn’tan actual phenomenon, it’snecessary to use a measuringinstrumentto determineit. Instrumentsthat can measureimpedance are impedance meters,LCR meters as well as impedance analyzer. There aremanymethods through which impedance maybe measured.

Bridge method

Thismethod makes use ofan electronic bridge circuit to determineanunidentifiedresistance. It requiresbalance adjustment tobeperformed using a galvanometer.While the method offersa high degree of accuracy(about 0.1%), it’s poorly suitedto measurements with high speed.

I-V method

This methodcalculates impedance by measuringthe voltagesthat cross a currentdetector and an unknownimpedance. Itcan also be usedfor measuringthose sampleswhich are ground.As the impedance increases,themethod becomes more pronetothe effects oftheVoltmeter.

The RF I -V method

This method employsthe samemeasurement principleslike the I-V method. Itpermits high-frequency measurementby using a circuit , whichcorresponds to the characteristic impedancecoaxial cables that have high frequencies andcoaxial connectors that are high-frequency.It’s not an easymethod to measure widebands becausethefrequency range used for measurementisrestrictedin the measurement head’s circuit.

Automatically balancedbridge method

This method uses the samefundamental measurement principles asthe bridge method. Itoffers coverage overan extensive frequency range(1from mHz up to 100 MHz).However, this coverageis not extended to higherfrequencies.A lot ofLCR metersemploy this method.

Each impedance analyzer approach has its ownadvantages and drawbacks, soyou’ll need to clearly definethe type of impedance thatyou’ll need to testprior to choosing the appropriatemethod to employ.

The use of an impedance gauge

The methodemployed to measure impedancedepends on the device beingutilized.For instance, Hioki’s LCRMeter IM3523can measure the impedancewith an extremely high level ofaccuracy in a varietyoffrequency settings.

  • 40 Hz measurement

  • 200measurement in Hz

In addition to standard measurement instruments, this one cancontinuously and quickly monitor differentparametersunder variousconditions(measurement frequency andthe signal level).

  • C-D+ESR Measurement of Capacitors

impedance analyzeralso allows for the saving ofup to 60 setsin measurement conditionsas well as up to128value of corrections for open/shortandlength correction for cables.Sets of settings can bequickly loadedfor increasedefficiency.

In addition, the instrument’s exteriorcontrol terminalscan be used to createautomatedtest lines more quickly.

Causes of instability in impedancemeasurement

Based on the measurement methodthat is being used, impedance metersmight return a different measurementevery time a measurementmade. Ifyour impedance meter’smeasured values do not stabilize make sure you check the following factors:

Parasitic components of the components beingdetermined

In addition to the designedvaluesfor resistance and reactance,componentscontain parasitic components thatcan cause a variance in measuredvalues.There are also variations in thelength ofthe lead that is connectedtocomponents as well as thedistance between themcancause measurements to fluctuate.

Measurementof the environment

The measurement of impedance results can beaffected by a wide range offactors, such asvariations in temperature notjustresistorsas well as capacitors and inductors as well asthe capacitance of the probe and the stray.

Thisis why it is necessary to take stepsincluding maintaining a stablemeasuring environment and averaging of multiplemeasurements instead ofusing a singlemeasurement tocalculatethevalue.

DC bias

DC biasor DC istinyamount of voltage present in measuringinstrumentsand circuits.For instance, it can occurwhen the probe and wirearemade from different materials. Theresultant thermal electromotive forcecreatesDC bias.

Summary

Impedance quantifies resistance toan AC current. Itsmeasurement requiresan instrument that is specifically designed for.As there are a numberofmeasurement techniques so it’s essential to pickthemost effective method, based onthe purpose of your measurement and also each method’sadvantages anddisadvantages.

Impedance measurement is extremelydelicate and is susceptible to variationsdue to various factors such asthe measurement environment, frequency as well asDC bias. Thismakes it necessary to performmethods like averaging of multiplemeasurements.

Applications

  • The measurement of impedance for the Smart Key/Immobilizer antenna

  • MLCC

  • Conductive polymer capacitors

  • Tantalum capacitors

How to Use

  • LCRMeasurement of meter principles

  • How to Use an LCR Meter: Basic Knowledge