EMC - a definition
EMC means nothing more than "an electronic or electrical product shall work as intended in its environment. The electronic or electrical product shall not generate electromagnetic disturbances, which may influence other products". In other words, EMC deals with problems of noise emission as well as noise immunity of electronic and electrical products and systems. Electromagnetic disturbances occur as conducted interference as well as radiated emissions and immunity problems.
Generally EMC, Electro Magnetic Compatibility, should really not be difficult to understand, but as you know, the devil is in the details. Let us explain the topic in a little bit more details. For those of you who are EMC-experts, we hope you excuse us for making some "non-scientific" simplifications. 
The word EMC does not include the influence of electromagnetic waves (either desired or undesired) on biological systems. This is a much larger field and is covered by the expression "EMCE" ("E" is for environmental), which is not the topic here and is also not the field in which EM TEST works.

Where EMC got started
The history of EMC
Let us go back in the history of EMC. EMC is older than you may believe.
We are all living with our history. The same is for EMC. You may not know, as many EMC experts also do not know, how everything was started. We want to give you a short summary of the history of EMC in Europe. The following is not given in great detail, but it does illustrate why we are where we are today in the EMC world.

The new age of communication in Europe began 1892 when the German Parliament voted to create the "Law of egraph in the German Empire". This was the first law in the world that dealt with influences of electromagnetic disturbances on products and installations in the field of egraph technique. This law also regulated the procedures to be followed in case such electromagnetic disturbances were found. People at that time had discovered very quickly that cables did disturb each other. The disturbances on egraph and ephone communication were the most severe. The German Society of Electrotechnicians, founded in 1893, was the foundation of what today is well known as VDE. Wilhelm von Siemens was one of the original founders of this famous society.

More than 110 years ago EMC was not a big matter but this was changed immediay in the evening of December 22 in 1920. On this night, the radio station of König Wusterhausen southeast of Berlin broadcasted the Christmas concert of the German mail officials. The concert was a live event and the audience included the German Chancellor Hermann Müller, who was close to the concert location in the famous castle of König Wusterhausen. The Chancellor was not very amused by the electrical noise interference generated by vehicles passing by and he gave strict orders to immediay prevent such disturbances. The hour of "Radiated Emission" had come and was then later on called EMC.

EMC standardization in the past
The first steps towards standardization ...
Germany was among the first to recognize the need to prevent and solve the problems of radiated emissions. In 1933, the international committee for radiated emissions, better known as CISPR was founded. Late in the 60's, concrete investigations were made to deal with the immunity of electrical products. In 1973 the International Electrotechnical Commission, the IEC, founded the technical committee TC77 whose function is to develop standards related to EMC.

In the 2nd World War knowledge of electromagnetic waves and their ability to create disturbances was used. During the war, radar technology was developed. Not only did the new communication technologies of radio, evision and ephone require electromagnetic compatibility, they were the driving force in changing from tube technology to transistors. The evolution of highly integrated chip technologies requires a broad understanding and use of EMC design experience.

As the technology progressed, legislation and standardization was developed to insure the harmony of the new sciences from an EMC standpoint.

Lets go back again to the German example. In 1927 the first edition of the "Deutsche Hochfrequenzgerätegesetz" was published. The recommendations of Chancellor Müller were successfully introduced although it took about 7 years to result in an official law. The new law was revised several times and was matched to the technical progress. This law was valid until December 31 of 1995 and was then replaced by the German EMC law, which is based on the European Directive.

Every product's reliability depends on EMC
No electrical product or installation can be designed seriously unless all aspects of EMC are taken into account. This is not only important for common products such as radios, evision sets, computers, ephones, washing machines, etc., but it is also especially important for complex products such as vehicles, aircraft, ships and large industrial installations. These are very sensitive to EMC problems and no one wants to accept serious disturbances within a big chemical plant.

Because of all the efforts made and being made to insure EMC compatibility, people start to believe that, after a certain time, all products are safe and immune. Sorry, but this has not come true as yet. Each new generation of engineers and technicians are again challenged by the issue of EMC with each new product and within each new installation. Practical solutions to EMC problems are not taught at universities. This can only be achieved with many years of experience in the field and testing. This is where EM Test can be of help.

EM Test has the task of educating engineers and technicians about EMC. EM Test can use its EMC experience to help all. Remember how this very interesting technical field began and developed. Only those who know the sources, and our sources are the basics of EMC, know where he has to go. We know the issues from the very beginning and will support you so that you better understand them. Let's go together a part of this way and let's keep in contact. By reading this message you have completed the first step.
電磁兼容(róng)性-定(dìng)義
EMC指的隻(zhī)是“電子產品或(huò)電子產品在(zài)其(qí)環(huán)境中的工(gōng)作原(yuán)理”。電子或電氣產品(pǐn)不應產(chǎn)生電磁(cí)幹(gān)擾(rǎo)，可(kě)能影(yǐng)響其他產品(pǐn)。換(huàn)句話(huà)說，EMC涉及電子(zǐ)電(diàn)氣產(chǎn)品和(hé)係統的噪聲發(fā)射和抗(kàng)噪(zào)聲問(wèn)題(tí)。電(diàn)磁(cí)幹擾主(zhǔ)要(yào)表(biǎo)現(xiàn)為(wéi)傳導(dǎo)幹(gān)擾和輻(fú)射發(fā)射和免疫(yì)問題。
一(yī)般來(lái)說電(diàn)磁兼(jiān)容，電磁(cí)兼(jiān)容(róng)性，真(zhēn)的不難(nán)理解，但(dàn)你知道，魔(mó)鬼是在細(xì)節(jié)。讓我們更(gēng)詳細地解(jiě)釋(shì)一下這個話題。對於(yú)你(nǐ)們(mén)這些EMC專家(jiā)來(lái)說(shuō)，我們希望你(nǐ)們原諒我(wǒ)們進行(háng)一(yī)些“非科(kē)學(xué)”的簡化。
EMC這(zhè)個(gè)詞不包(bāo)括(kuò)電磁波(bō)（無(wú)論是(shì)期(qī)望的還是(shì)不(bù)希望(wàng)的(dí)）對生物係統(tǒng)的影(yǐng)響(xiǎng)。這是一(yī)個(gè)更(gēng)大的領域，由“東蒙大拿教(jiào)育學院(yuàn)”（“E”是環境），這不是(shì)今(jīn)天的主題(tí)，也不在(zài)EM測試(shì)工作的領(lǐng)域。

EMC在哪(nǎ)裏(lǐ)開始(shǐ)的(dí)
電磁(cí)兼(jiān)容的(dí)歷史
讓(ràng)我(wǒ)們(mén)回到EMC的(dí)歷(lì)史。電(diàn)磁(cí)兼(jiān)容比(bǐ)你(nǐ)想象的要老(lǎo)。
我(wǒ)們都生(shēng)活在我(wǒ)們的(dí)歷史(shǐ)中(zhōng)。EMC也(yě)是如此。你(nǐ)可(kě)能(néng)不(bù)知(zhī)道(dào)，很多EMC專(zhuān)家也不(bù)知道，一(yī)切都(dū)是怎麼開始(shǐ)的(dí)。我(wǒ)們想給你(nǐ)簡要(yào)介(jiè)紹一(yī)下(xià)歐(ōu)洲(zhōu)電(diàn)磁兼容的歷史。下麵的(dí)內容並(bìng)不(bù)是非(fēi)常詳細的，但它(tā)確實說(shuō)明(míng)了我們今天在EMC世界中的地位(wèi)。

歐洲的(dí)新通訊時代(dài)開始於(yú)1892年(nián)，當時德國(guó)議會(huì)投票決(jué)定建立(lì)德意誌帝國的(dí)《電(diàn)報(bào)法(fǎ)》。這是(shì)世(shì)界(jiè)上(shàng)*條處理電(diàn)報(bào)技術領域中電磁幹(gān)擾(rǎo)對產(chǎn)品(pǐn)和裝置影響(xiǎng)的(dí)法(fǎ)律。該(gāi)法還規定(dìng)了在(zài)發(fā)現電磁幹擾的情況下應遵循(xún)的程(chéng)序。當時的(dí)人們(mén)很快就發現(xiàn)電纜(lǎn)確實互相幹擾。電(diàn)報(bào)和(hé)通信(xìn)的幹擾zui為嚴(yán)重。對電工的德國社會(huì)，成(chéng)立於1893，是*的(dí)VDE是什麼今(jīn)天(tiān)的基礎。Wilhelm von Siemens是(shì)這個(gè)社(shè)會的(dí)創始人之(zhī)一(yī)。

110多(duō)年(nián)前EMC並不(bù)是(shì)一(yī)件大(dà)事(shì)，但在1920 12月22日(rì)的(dí)晚上，這種情況(kuàng)立(lì)即改(gǎi)變了(liǎo)。在(zài)這個晚上(shàng)，KöNIG Wusterhausen東南柏林電台播出(chū)的德國(guó)郵政官員的(dí)聖誕音樂會(huì)。這場(cháng)音(yīn)樂(lè)會(huì)是一個生活(huó)事件和(hé)觀眾包(bāo)括德(dé)國(guó)總理(lǐ)Hermann Müller，誰是接近演唱會地(dì)點在的KöNIG武斯特(tè)豪(háo)森城堡(bǎo)。校長對過(guò)路車輛(liàng)產(chǎn)生(shēng)的(dí)電(diàn)噪音幹擾不甚感(gǎn)興趣(qù)，他(tā)下令立(lì)即阻(zǔ)止這(zhè)種幹(gān)擾(rǎo)。“輻射(shè)發射(shè)”的時間已經到(dào)來(lái)，後來稱為(wéi)電(diàn)磁(cí)兼容。

電(diàn)磁(cí)兼(jiān)容標(biāo)準(zhǔn)化
走向標準化(huà)的*步…
德國(guó)是(shì)zui先(xiān)認識(shí)到需(xū)要防止(zhǐ)和(hé)解(jiě)決(jué)輻射(shè)排放問題的(dí)國(guó)家之(zhī)一。1933，輻射(shè)委(wěi)員(yuán)會，更好地(dì)稱(chēng)為(wéi)CISPR成(chéng)立(lì)。60年底(dǐ)，就(jiù)電(diàn)氣產(chǎn)品(pǐn)的豁免問題(tí)進行了具(jù)體(tǐ)調(tiáo)查。1973電工(gōng)委員(yuán)會，IEC，成(chéng)立了技(jì)術委(wěi)員會TC77其(qí)職能(néng)是製(zhì)定(dìng)相關(guān)的(dí)電(diàn)磁(cí)兼(jiān)容(róng)標準。

在(zài)第(dì)二(èr)次世界大戰中(zhōng)，電(diàn)磁波的知識和它們(mén)製造幹(gān)擾的(dí)能力被(bèi)使用了(liǎo)。戰爭(zhēng)期(qī)間，雷(léi)達技術(shù)得到發展(zhǎn)。無(wú)綫(xiàn)，電(diàn)視，等(děng)新的通信技術不僅要求電(diàn)磁兼(jiān)容，而(ér)且(qiě)是從管(guǎn)技(jì)術(shù)向晶體(tǐ)管轉換(huàn)的驅動(dòng)力。高度集成的(dí)芯片(piàn)技術的發(fā)展需要廣(guǎng)泛(fàn)理解(jiě)和使用EMC設計經驗。

隨著(zhuó)技術的(dí)進步，立法(fǎ)和標(biāo)準化的(dí)發(fā)展，以確保(bǎo)和諧的(dí)新科(kē)學(xué)，從EMC的(dí)立場(cháng)。

讓我(wǒ)們再回到德(dé)國(guó)的例子(zǐ)中。1927的(dí)*個版本的“德意(yì)誌hochfrequenzgerätegesetz”出版。校長(cháng)ü建(jiàn)議(yì)M ller成功引進了雖(suī)然(rán)大約(yuē)花(huā)了7年的結果在一(yī)個正(zhèng)式的(dí)法律。新(xīn)法(fǎ)律(lǜ)修訂了幾次，與(yǔ)技(jì)術進步(bù)相匹(pǐ)配。該法(fǎ)有(yǒu)效期至1995 12月(yuè)31日，其後(hòu)由德(dé)國(guó)EMC法(fǎ)取(qǔ)代，該法以(yǐ)歐洲(zhōu)指令為(wéi)基礎。

每個(gè)產品的可靠性(xìng)取(qǔ)決於EMC。
除非(fēi)考慮到EMC的所(suǒ)有方(fāng)麵，否則不(bù)能認真(zhēn)設(shè)計(jì)電氣產品或安裝。這(zhè)不僅(jǐn)對(duì)收音機，電(diàn)視機，計算(suàn)機(jī)，，洗衣(yī)機等(děng)常見產(chǎn)品(pǐn)很重要，而(ér)且對諸如(rú)汽車，飛機(jī)，輪船和大型(xíng)工(gōng)業裝置等復雜(zá)產品也特別重要(yào)。這些對EMC問題非常(cháng)敏感(gǎn)，沒有人(rén)願(yuàn)意接受(shòu)大型化(huà)工廠(chǎng)的嚴重(zhòng)幹擾(rǎo)。

由(yóu)於所有(yǒu)的努力(lì)和確(què)保EMC兼容性(xìng)的(dí)努(nǔ)力，人們開始相信，經(jīng)過一定時(shí)間(jiān)，所有產品(pǐn)都(dū)是(shì)安全和免(miǎn)疫的。對(duì)不起(qǐ)，這還沒有實(shí)現。每一(yī)代(dài)的工(gōng)程(chéng)師(shī)和(hé)技(jì)術人(rén)員都再次(cì)受(shòu)到電(diàn)磁(cí)兼容問題(tí)的(dí)困擾。大(dà)學(xué)不(bù)教授電(diàn)磁兼容問(wèn)題的(dí)實際(jì)解(jiě)決方(fāng)案。這隻能通(tōng)過多年的實地經(jīng)驗和測(cè)試來實現(xiàn)。這是EM測試可(kě)以幫(bāng)助的(dí)地(dì)方(fāng)。

電磁(cí)測(cè)試對(duì)工程技術(shù)人員進(jìn)行電(diàn)磁兼(jiān)容教(jiào)育。EM測(cè)試(shì)可(kě)以利(lì)用它的EMC經驗來幫助(zhù)所有人。記(jì)住這(zhè)個非常有趣的技(jì)術領(lǐng)域是如(rú)何開(kāi)始(shǐ)和發(fā)展起來(lái)的(dí)。隻有(yǒu)那(nà)些(xiē)知道(dào)來(lái)源和我們(mén)的來源是EMC的基(jī)礎，知道(dào)他必須(xū)去哪(nǎ)裏。我們從(cóng)一開始就(jiù)知道(dào)問(wèn)題，並會支持(chí)你(nǐ)，以便(biàn)你(nǐ)更(gēng)好(hǎo)地(dì)理(lǐ)解(jiě)它們。讓我們(mén)一(yī)起(qǐ)走這條路的一(yī)部分，讓我們(mén)保持(chí)。通過(guò)閱(yuè)讀這條信(xìn)息，你已經完成(chéng)了*步(bù)。