What is the difference between an LCR meter and a multimeter?
LCR meter, as the name implies, is a special measurement tool used to measure the parameters of the certificate of electrical components, L, refers to the inductance, c, refers to the capacitance, R, refers to the resistance. In addition, the LCR meter cannot measure other things, and it is necessary to measure inductance, resistance or capacitance when the circuit is powered off. Because it is a special instrument, the measurement precision is high and the accuracy is strong.
In addition to measuring the inductance of the above-mentioned resistance, capacitance and inductance, the multimeter can also measure AC and DC voltage, current, power frequency, etc. in different gears. Although it has more functions, its precision is not very accurate.
To put it simply, the LCR meter measures the intrinsic parameters of the separated components, such as the resistance value of the resistor, the capacitance value of the capacitor, etc., and it generally needs to be tested independently when the power is turned off. The multimeter is a multi-functional measuring instrument, it can test the separation components, it can also test the electrical signal characteristics, and it also has some other measurement functions.
1. The principle of LCR meter detection components
According to the actual use conditions and combinations of the components to be tested. The LCR meter has two detection modes: series mode and parallel mode. The series mode is based on the impedance Z of the detection components, and its basic principle is shown in Figure 1; the parallel mode is based on the admittance Y of the detection components
The sine wave signal source inside the Vs internal relay in circle 1 and circle 2, the internal resistance of the signal source in Rs, the digital pressure meter in V, and the digital current meter in A. In addition, there is a digital phase stealer not shown in the circle installed inside the weapon. After the user connects the component to be tested to the sensor, the digital current meter will measure the current I of the component to be tested, and the digital pressure meter will measure the voltage V of the terminal C of the component to be tested. , the digital phase adjuster will measure the phase angle 8 between the pressure V and the current I. The test results are stored in three storage units of the internal computer of the weapon.
With the three data of V, I, and B, the microcomputer inside the device will automatically calculate the parameters that the user wants to detect.
2. The parameters that can be detected by the LCR meter
In the instruction manual of the instrument, the measurement parameter selection table shown in Table 1 is listed. In the table, Primary is the main parameter column, and Secondary is the secondary parameter column. Z in the table is impedance, Y is admittance, R is resistance, G is conductance, Cp is parallel capacitance, Cs is series capacitance, Lp is parallel inductance, Ls is series inductance, and R is the phase angle of voltage relative to current, X is reactance, B is susceptance, D is loss factor, Q is quality factor, Rp is parallel resistance, Rs is series resistance.
Before testing a component or an assembly of two components, the user must select a main parameter to be tested from the main parameter column and a secondary parameter to be tested from the secondary parameter column according to their holding points. A main parameter is paired with a secondary parameter, and there are a total of 20 combination schemes to choose from. After a measurement is completed, the measured values and units of the primary and secondary parameters will be displayed on the LCD screen of the instrument.
