{"id":1372,"date":"2024-07-10T19:17:47","date_gmt":"2024-07-10T13:47:47","guid":{"rendered":"https:\/\/study.madeeasy.in\/?p=1372"},"modified":"2025-07-16T15:04:45","modified_gmt":"2025-07-16T09:34:45","slug":"piezo-electric-transducers","status":"publish","type":"post","link":"https:\/\/www.madeeasy.in\/study\/ee\/electrical-electronic-measurements\/piezo-electric-transducers","title":{"rendered":"Piezo Electric Transducers"},"content":{"rendered":"<p style=\"text-align: justify;\">When a varying potential applied to the proper axis of a crystal, there is a change in dimension of the crystal which is known as \u201cPiezo-electric effect\u201d. The reverse effect is also true, i.e., if the dimensions of the crystal are changed by the application of a mechanical force, an electric potential appears across certain surface of the crystal due to the displacement of charges. The elements which exhibit piezo-electric qualities are called as \u201cElectro-resistive elements\u201d.<br \/>\nBelow figure describes the phenomena of piezo-electric effect on a piezo-electric crystal with the application of a force, F<\/p>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-1374 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/piezo-electric-crystal.jpg\" alt=\"Piezo Electric Crystal\" width=\"508\" height=\"244\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/07\/piezo-electric-crystal.jpg 508w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/07\/piezo-electric-crystal-300x144.jpg 300w\" sizes=\"auto, (max-width: 508px) 100vw, 508px\" \/><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_79_1 ez-toc-wrap-left counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.madeeasy.in\/study\/ee\/electrical-electronic-measurements\/piezo-electric-transducers\/#Classification-of-Piezo-Electric-Materials\" >Classification of Piezo-Electric Materials:<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.madeeasy.in\/study\/ee\/electrical-electronic-measurements\/piezo-electric-transducers\/#8-Cable-Connection-Model-of-Piezo-electric-Transducers\" >8. Cable Connection Model of Piezo-electric Transducers:\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.madeeasy.in\/study\/ee\/electrical-electronic-measurements\/piezo-electric-transducers\/#9-Properties-of-Piezo-Electrica-Crystals\" >9. Properties of Piezo-Electrica Crystals:<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.madeeasy.in\/study\/ee\/electrical-electronic-measurements\/piezo-electric-transducers\/#Advantages-of-Instrument-Transformers\" >Advantages of Instrument Transformers<\/a><\/li><\/ul><\/nav><\/div>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"Classification-of-Piezo-Electric-Materials\"><\/span><strong>Classification of Piezo-Electric Materials:<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p style=\"text-align: justify;\"><strong>(i) Natural Group:<\/strong>\u00a0Natural group include quartz and rochelle salt<br \/>\n<strong>(ii) Synthetic Group:<\/strong> Synthetic group include materials like Lithium Sulphate, Ethylene Diamine Tartarate,<br \/>\nPotassium Dihydrogen Phosphate, Barium Titanate, Ammonium Dihydrogen Phosphate, Lead Zirconate, etc.<\/p>\n<p style=\"text-align: justify;\">All piezo-electric materials are electrical insulators.<br \/>\n1. Piezo-electric effect is direction sensitive. A tensile force produces a voltage of one polarity while a compressive force produces a voltage of opposite polarity.<br \/>\n2. Two metal electrodes are placed on each side of the material to bring out the charge. Hence, a piezo-electric material is equivalent to a charge generator and a capacitor.<br \/>\n3. Let the applied force on the piezo-electric crystal be F.<\/p>\n<p style=\"text-align: justify;\">Q = charge<br \/>\nt = thickness of the crystal<br \/>\nE = electric field intensity<br \/>\nP = pressure applied<br \/>\ng = voltage sensitivity of the crystal<br \/>\nQ \u221d F<br \/>\nQ = dF<\/p>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-1399 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/classification-of-piezo.jpg\" alt=\"Classification of Piezo\" width=\"553\" height=\"187\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/07\/classification-of-piezo.jpg 553w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/07\/classification-of-piezo-300x101.jpg 300w\" sizes=\"auto, (max-width: 553px) 100vw, 553px\" \/><\/p>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1400\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/sensitivity.jpg\" alt=\"Sensitivity\" width=\"243\" height=\"34\" \/><\/p>\n<p style=\"text-align: justify;\">4. Piezoelectric transducers are suitable for dynamic pressure or force measurement.<br \/>\n5. For static inputs, the internal charges fastly discharges and hence the output becomes zero.<br \/>\n6. Equivalent Circuit of Piezo-electric Transducers:<\/p>\n<p style=\"text-align: justify;\">Below figure shows an equivalent circuit of a piezo-electric transducer<\/p>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-1453 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/piezo-electric-transducer.jpg\" alt=\"Piezo Electric Transducer\" width=\"598\" height=\"237\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/07\/piezo-electric-transducer.jpg 598w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/07\/piezo-electric-transducer-300x119.jpg 300w\" sizes=\"auto, (max-width: 598px) 100vw, 598px\" \/><\/p>\n<p style=\"text-align: justify;\">7. Piezo-electric transducers are mainly used for measurement of displacement. They can be used for measurement of force, pressure or acceleration. These quantities when measured with piezo-electric transducers are first converted into displacement and the displacement is then, applied to these transducers to produce an output voltage.<\/p>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"8-Cable-Connection-Model-of-Piezo-electric-Transducers\"><\/span><strong>8. Cable Connection Model of Piezo-electric Transducers:\u00a0<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p style=\"text-align: justify;\">Below figure shows the cable connection model of piezo-electric transducer. It shows the transducer, the connecting cable and the amplifier as a unit. The impedance of the transducer is very high and hence an amplifier with a high input impedance has to be used in order to avoid loading effect.<\/p>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-1454 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/cable-connecction-model.png\" alt=\"Cable connection model\" width=\"421\" height=\"374\" srcset=\"https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/07\/cable-connecction-model.png 421w, https:\/\/www.madeeasy.in\/study\/wp-content\/uploads\/2024\/07\/cable-connecction-model-300x267.png 300w\" sizes=\"auto, (max-width: 421px) 100vw, 421px\" \/><\/p>\n<p style=\"text-align: justify;\">Here,<\/p>\n<p style=\"text-align: justify;\">Rp = Leakage resistance of transducer<br \/>\nCp = Capacitance of transducer<br \/>\nCc = Cable capacitance<br \/>\nCA = Amplifier capacitance<br \/>\nRA = Amplifier resistance<\/p>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-1455 size-full\" src=\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/capacitance.jpg\" alt=\"Capacitance\" width=\"177\" height=\"88\" \/><\/p>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"9-Properties-of-Piezo-Electrica-Crystals\"><\/span><strong>9. Properties of Piezo-Electrica Crystals:<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p style=\"text-align: justify;\">The desirable properties of piezo-electric materials are stability, high output insensitivity to temperature and humidity and the ability to be formed into most desirable shape. Quartz is the most stable piezo-electric material. However, its output is quite small. On the other hand Rochelle salt provides the highest output but it can be worked over a limited humidity range and has to be protected against moisture.<\/p>\n<p style=\"text-align: justify;\">Barium titanate has the advantage that it can be formed into variety of shapes and sizes since it is polycrystalline. It also has a higher dielectric constant.<\/p>\n<p style=\"text-align: justify;\">Natural crystals possess higher mechanical and thermal stability, can withstand higher stresses, have low leakage and have a good frequency response. The synthetic materials, in general have a higher voltage sensitivity.<\/p>\n<table class=\"table table-striped table-bordered table-condensed\" style=\"margin: 0 auto; width: 99%;\">\n<tbody>\n<tr>\n<th width=\"107\">Material<\/th>\n<th><strong>Voltage sensitivity<\/strong> <strong>(<em>g<\/em>)<\/strong><\/th>\n<th><strong>Permittivity<\/strong> <strong>(<\/strong>e<strong>) \u00a0<\/strong><\/th>\n<th><strong>Charge sensitivity (<em>d<\/em>)<\/strong><\/th>\n<\/tr>\n<tr>\n<td width=\"107\">\n<p style=\"text-align: center;\">Barium titanate<\/p>\n<\/td>\n<td style=\"text-align: center;\" width=\"120\">12 \u00d7 10<sup>\u20133<\/sup><\/td>\n<td style=\"text-align: center;\" width=\"106\">12.5 \u00d7 10<sup>\u20139<\/sup><\/td>\n<td width=\"117\">\n<p style=\"text-align: center;\">150<\/p>\n<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: center;\" width=\"107\">Quartz<\/td>\n<td style=\"text-align: center;\" width=\"120\">50 \u00d7 10<sup>\u20133<\/sup><\/td>\n<td style=\"text-align: center;\" width=\"106\">40.6 \u00d7 10<sup>\u201312<\/sup><\/td>\n<td width=\"117\">\n<p style=\"text-align: center;\">2<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"text-align: justify;\"><strong>Advantage of Piezo-electric Transducers<br \/>\n<\/strong><\/p>\n<ul style=\"text-align: justify;\">\n<li>It\u2019s input impedance is high. So, loading effect is minimum<\/li>\n<li>Good dynamic response<\/li>\n<li>Compact in size<\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><strong>Disadvantage of Piezo-electric Transducers<\/strong><\/p>\n<p style=\"text-align: justify;\">Lack of steady state response.<\/p>\n<ul style=\"text-align: justify;\">\n<li>The use of piezo-electric transducers is confined primarily to dynamic as the voltage developed by application of strain is not held under static conditions. Hence, the elements are primarily used in the measurement of such quantities as surface roughness and in accelerometers and vibration pickups.<\/li>\n<li>Ultrasonic generator elements also use barium titanate, a piezo-electric material. Such elements are used in industrial cleansing apparatus and also in underwater detection system known as sonar.<\/li>\n<\/ul>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"Advantages-of-Instrument-Transformers\"><\/span><strong>Advantages of Instrument Transformers<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p style=\"text-align: justify;\">Instrument transformers are widely used for the precise and routine measurement of voltage and current because of the following advantages:<\/p>\n<ol>\n<li style=\"text-align: justify;\">Several instruments can be operated from a single instrument transformer (CT or PT).<\/li>\n<li style=\"text-align: justify;\">The measuring circuit is isolated from the high voltage power-circuit which ensures safety of the operator.<\/li>\n<li style=\"text-align: justify;\">There is low power consumption in the measuring circuit.<\/li>\n<li style=\"text-align: justify;\">The replacement of instrument transformer is easier.<\/li>\n<li style=\"text-align: justify;\">Instrument transformers are used for the measurement of large magnitude of current and voltages.<\/li>\n<li style=\"text-align: justify;\">Instrument transformers produce practically the same instrument reading regardless of the constants of the instruments.<\/li>\n<li style=\"text-align: justify;\">Instrument transformers helps in reducing overall cost, since various instruments including metering, relaying, diagnostic etc. can all be connected to the same instrument transformer<\/li>\n<\/ol>\n<p style=\"text-align: center;\"><a class=\"btn btn-danger\" role=\"button\" href=\"https:\/\/study.madeeasy.in\/ee\/electrical-electronic-measurements\/cathode-ray-tube\/\" target=\"_blank\" rel=\"noopener\">&lt;&lt; Previous<\/a> | <a class=\"btn btn-success\" role=\"button\" href=\"https:\/\/study.madeeasy.in\/ee\/electrical-electronic-measurements\/quality-factor-meter\/\" target=\"_blank\" rel=\"noopener\"> Next &gt;&gt;<\/a><br \/>\n<strong> Must Read: <\/strong> <a href=\"https:\/\/study.madeeasy.in\/subjects\/what-are-the-electrical-and-electronics-measurements\/\" target=\"_blank\" rel=\"noopener\"><strong>What are the Electrical and Electronics Measurements?<\/strong><\/a><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>When a varying potential applied to the proper axis of a crystal, there is a change in dimension of the<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[389,5],"tags":[415,413,414,412],"class_list":["post-1372","post","type-post","status-publish","format-standard","hentry","category-electrical-electronic-measurements","category-ee","tag-cable-connection-model-of-piezo-electric-transducers","tag-electro-resistive-elements","tag-properties-of-piezo-electrica-crystals","tag-voltage"],"_links":{"self":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/1372","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/comments?post=1372"}],"version-history":[{"count":0,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/1372\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/media?parent=1372"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/categories?post=1372"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/tags?post=1372"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}