Q-meter

Quality factors are used to measure the quality factor and inter-turn capacitance of coils, capacitance and loss tangent of capacitors, the quality factor and natural resonant frequency of loops , impedance , as well as to study the properties of dielectrics .

The Q-meter is a sequential oscillatory circuit formed by an inductor , the parameters of which are measured, and an exemplary capacitor of variable capacitance , which provides tuning of the circuit to resonance at the frequency of the supply voltage. Inductance value${\displaystyle {\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">L</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">x</span></span>}}}$ {\ displaystyle L_ {x}}   equally:

${\displaystyle {\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">L</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">x</span></span>}}<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">=</span></span>\frac{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">one</span></span>}}{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">four</span></span>}{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">\pi </span></span>}}^{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}}{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">f</span></span>}}^{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">2</span></span>}}{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">C</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">0</span></span>}}}}${\ displaystyle L_ {x} = {\ frac {1} {4 \ pi ^ {2} f ^ {2} C_ {0}}}}  

Where${\displaystyle \mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">f</span></span>}}$ {\ displaystyle f}   - frequency${\displaystyle {\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">C</span></span>}}_{\mathrm{<span\; class="mwe-math-element"><span\; class="mwe-math-mathml-inline\; mwe-math-mathml-a11y"\; style="display:\; none;">0</span></span>}}}$ {\ displaystyle C_ {0}}   - capacity of the reference capacitor

• E4-10 (1 ... 100) - kHz
• E4-11 (30 ... 300) - MHz
• E9-4 - 50 kHz ... 35 MHz
• VM 560 - from 50 kHz to 35 MHz
• MQ-1601 - 15.5 kHz to 50 MHz

• Measurement Frequency Range
• Q measurement range and permissible measurement error
• Capacitance measuring range and permissible measurement error
• Inductance measurement range and permissible measurement error

Literature

• Handbook of radio measuring instruments : In 3 tons; Ed. V. S. Nasonova - M.: Sov. radio, 1979
• Handbook of electronic devices : In 2 tons; Ed. D.P. Linde - M .: Energy, 1978
• Kushnir F.V. Electroradio - measurements - L .: Energoatomizdat, 1983 (inaccessible link)
• B.V. Dvoryashin, L.I. Kuznetsov. Radio engineering measurements - M .: Sov. radio, (link unavailable) 1978
• A. Ya. Akmentinsh Amateur Koumeter - L .: Energoatomizdat, (inaccessible link) 1970

Regulatory and technical documentation

• GOST 11286–69 Q-meters. Technical requirements
• GOST 8.498-98 State system for ensuring the uniformity of measurements. State verification scheme for measuring instruments of electric quality factor
• E4-11 Q-meter. Technical description and instruction manual

• Experimental Q meter
• SIMPLE Q-METP
• Inductor, Q factor, capacitance, RF voltage meter
• RF Coil Q factor meter
• QUALITY METER (KUMETR) TYPE КВ-1
• V. Stepanov. Digital Q-factor
• Computer laboratory stand "Qmeter"
• Photo - BM 560 Q factor meter

• Immitance Meter
• Ohmmeter
• Q factor
• Radio measuring instruments