5 Simple Techniques For impedance analyzer

Learnto operatean impedancegauge!Fundamental measurement methods

Overview

Impedance metersmeasure impedance,in other words, the amount of resistance that flows throughanAC.(AC). Thispage offers a thoroughintroduction to basic knowledge aboutimpedance, ways to measureimpedance and the best wayto make use of an impedance gauge.

What isimpedance?

Let's start by definingimpedance. Inshort, impedanceisa measure ofresistance to thecurrentthat isAC current.AC current.

When you connect an electricdevice, motor,orotherelectronic device withanACsupply of power,current is able to flowthrough thedevice's circuitry. Impedance iscalculatedthrough the division of the voltage inthe circuit withits current. Inshort, impedance canbedescribed as restricting theflow of currentwithinanAC circuit. Impedance isindicated byit'ssymbol "Z" and measured inohms(O) which is the sameinstrument used to measureDC resistance. Thehigher the impedance,thegreater resistance is thereto theflow of current.

How is impedance measured?

Because impedance is notvisible, it'srequired to employ a measuringinstrumentto quantifyit. Instrumentsthat can measureimpedance include 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 determineanunknownresistance. It requiresbalance adjustment tobeaccomplished using a gaussometer.Although the technique providesthe greatest degree of accuracy(about 0.1 percent) It's not the best suitedto measurements with high speed.

I-V method

This methoddetermines impedance by measuringthe voltagesacross a currentdetection resistor , and an unknownimpedance. Itis also usedto testsamplesin which the sample is grounded.When the impedance grows,themethod becomes more pronetothe effects ofthevoltage gauge.

The RF I -V method

This method followsthe samefundamental measurement principlethat is used in the I-V method. Itpermits measurement of high-frequency impedanceby using a circuit whichmatches the characteristic impedancethe coaxial cable with high-frequency andthe high-frequency connector.It's not an easymethod for wideband measurements becausethefrequency range for measurementisrestricteddue to the transformer of the testing head.

Automatically balancedbridge method

The method used here is based on thefundamental measurement concept asthis method, called the bridge. Itallows coverage ofa broad frequency band(1mHz to 100 MHz).However, that coveragedoes not extend to highfrequencies.A large number ofLCR metersutilize this method.

Each impedance analyzer technique has its ownadvantages and disadvantages, thereforeyou must clearly definethe kind of impedanceyou'll need to determinebefore deciding on the besttechnique to choose.

The use of an impedance gauge

The methodused to measure the impedanceis determined by the instrumentutilized.For instance, Hioki's LCRMeter IM3523measures impedancewith an extremely high level ofprecision across a broad rangeoffrequency settings.

• 40 Hz measurement
• 200milliseconds

In addition to the normal measurement the instrument is able toconstantly and rapidly measure variousparametersin variouscircumstances(measurement frequency andthe signal level).

• C-D+ESR Measurement of Capacitors

impedance analyzer can also savethe equivalent of 60 setsof measurement conditionsin addition to up to128value of corrections for open/shortandlength correction for cables.Groups of settings can beimmediately loadedfor increasedefficiency.

In addition, the instrument's externalcontrol terminalspermit you to designautomatedtesting lines much faster.

Impedance measurement causes instability.measurement

Depending on the measurement methodthat is being used, impedance meterscould return a different valueeach time a measurement isperformed. Ifyour impedance meter'smeasured values do not stabilize, check the following:

The parasitic component of these components is beingdetermined

In addition to the designedvaluesfor reactance and resistance,componentscan also be affected by parasitic elements thatresult in a variation in the measuredvalues.There are also variations in thelength ofleads that connecttocomponents as well as thedistance between themmayresult in measured values varying.

Measurementof the environment

The results of Impedance measurements areaffected by a range ofconditions, includingvariations in temperature notonlyresistorsas well as capacitors and inductors as well asthe capacitance of probes and stray capacitance.

Thisrequires stepsthat are consistent, such as maintaining ameasurement space and averaging severalmeasurements instead ofmaking a singlemeasurement tocalculatetheamount.

DC bias

DC biasrefers to asmallvoltage that can be found in measurementinstrumentsand circuits.For example, it occurswhen the probe and wirearemade from different components. Theresultant thermal electromotive forcecan causeDC bias.

Summary

Impedance quantifies resistance toan AC current, and itsmeasurement requiresan instrument that is specifically designed for.Since there are a varietyofmethods for measuring that you can choose from, it is important to selectthebest method based onyour needs and the method'sadvantages anddisadvantages.

Impedance measurements are extremelydelicate and prone to variabilitydue to factors such asthe measurement's environment, frequency as well asDC bias. Thischaracteristic requiresmethods like averaging of multiplemeasurements.

Applications

• Impedance measurement for Smart Keys/Immobilizers antennas
• MLCC
• Conductive polymer capacitors
• Tantalum capacitors

How to Use

• LCRMeter measurement principles
• How to Use an LCR Meter: Basic Knowledge