measuring instrument The LCR tester is generally used to measure the capacitance of a ceramic capacitor. Measuring principle A representative measurement of the LCR tester is shown in the figure for the self-balancing bridge method. The principle is as follows. DUT Device Under Test Abbreviation, refers to the measurement object. The high-gain amplifier automatically adjusts the gain so that the current through resistor R equals the current through the DUT. The DUT low side (L side in the figure) is always at virtual ground (potential = 0). The input voltage E1 and the output voltage E2 at this time can be used to measure the phase angle as shown below. E1 = | E1 | ∠θ1 = | E1 | cos θ1 + j | E1 | sin θ1 E2 = | E2 | ∠θ2 = | E2 | cosθ2 + j | E2 | sinθ2 From these data and the feedback resistor R, the impedance Zx of the DUT is found. Zx = R? E1 / E2 = R? | E1 / E2 |? {Cos (θ1-θ2) + jsin (θ1-θ2)} In fact, the Department of Rx, the imaginary part of the Xx, obtained by Xx Xx = j / ωCx DUT capacitance can be calculated Cx. Precautions When measuring the capacitance of a ceramic capacitor, it must be performed under the correct measurement conditions listed on the data sheets and other related information. It should be noted that because of the nominal value of the capacitor and other conditions are also different. The conditions mentioned here, mainly refers to the measurement before the heat treatment, measuring voltage, the number of measurement frequency. In addition, since the residual impedance and admittance components of the measurement terminals, including the measurement cable, actually affect the measurement results, the measurement terminals need to be corrected. Since the calibration of the measurement terminal is a method that measures the value of the terminal block directly touching the part of the DUT and subtracts the impedance and other components from the measurement result, it is necessary to measure the correction value in advance. Corrections will usually use short-circuit correction and open-circuit correction. Non-Woven Protective Products,Bouffant Head Cap,Medical Surgical Doctor Cap,Disposable Cpe Shoe Covers Shaoxing Lifecare International Trading Co., Ltd , https://www.sx-lifecare.com