\n<\/strong><\/h2>\n
\u2022 Q-meter works on the principle of series resonance.
\n\u2022 Figure given below shows a series RLC circuit.<\/p>\n
![\"Series](\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/series-rlc-circuit.jpg\")
<\/p>\n
![\"Phaser](\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/phaser-diagram.jpg\")
<\/p>\n
Therefore, if the input voltage is constant, voltage across the capacitor is magnified Q times and a voltmeter can be connected across the capacitor which can be calibrated to read the value of Q directly.<\/p>\n
Practical Circuit of Q-meter It consists of a variable radio frequency oscillator which delivers a current to a low shunt resistance, Rsh which is order of 0.02 \u2126 (typical value). The voltage is measured by a thermocouple voltmeter. A calibrated standard variable capacitor C is used for getting the series resonance condition. An electronic voltmeter is connected across this capacitor C. The coil under test is connected between the terminals T1 and T2.<\/p>\n 1. Measurement of Quality Factor of Test Coil<\/strong><\/p>\n The test coil is connected between terminals T1 and T2. The oscillator is set to the desired frequency and then, the capacitor, C is adjusted to get the series resonance condition.<\/p>\n Let the coil resistance and inductance be R and L respectively,<\/p>\n Note:<\/strong><\/p>\n To get minimum error, the shunt resistance should be very small. As Rsh of the order of m\u2126 therefore, QT \u2248 Qm. 2. Measurement of Unknown Capacitance 3. Measurement of Unknown Inductance<\/strong><\/p>\n 4. Measurement of Self Capacitance<\/strong><\/p>\n 5. Measurement of Unknown Resistance<\/strong><\/p>\n << Previous<\/a> | Next >><\/a><\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" A quality factor meter is an instrument which is used to measure the value of storage factor Q directly and<\/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":[420,416,418,419,417],"class_list":["post-1464","post","type-post","status-publish","format-standard","hentry","category-electrical-electronic-measurements","category-ee","tag-applications-of-q-meter","tag-practical-q-meter","tag-quality-factor-of-test-coil","tag-test-coil","tag-voltmeter"],"_links":{"self":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/1464","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=1464"}],"version-history":[{"count":0,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/1464\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/media?parent=1464"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/categories?post=1464"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/tags?post=1464"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n<\/strong>
\nBelow figure shows a practical Q-meter<\/p>\n![\"Practical](\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/practical-q-meter.jpg\")
<\/p>\nApplications of Q-meter<\/strong><\/h3>\n
![\"](\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/measurement-of-quality-factor-of-test-coil.jpg\")
<\/p>\n
\nTherefore, the true value of quality factor of the coil is obtained when Rsh is maintained in m\u2126 range (can be neglected).<\/p>\n
\n<\/strong><\/p>\n\n
![\"Unknown](\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/unknown-capacitance.jpg\")
<\/sub><\/li>\n![\"](\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/measurement-of-unknown-capacitance.jpg\")
<\/sub><\/p>\n![\"Frequencies\"](\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/frequencies.jpg\")
<\/p>\n![\"Test](\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/test-coil.jpg\")
<\/p>\n![\"Unknown](\"https:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/07\/unknown-resistance.jpg\")
<\/p>\n