LQ-9101
User Manual
7.9 The higher the Q value measured, the larger the Q value?
is.normal Q = Xs/Rs, especially if Rs is very small (Q is very high). Due to the limited accuracy of
the bridge, Rs is not stable. Therefore, the higher the Q, the larger the jitter is, and the stronger the stable
display is impossible.
This is generally the case: the higher the Q, the more unstable and the greater the absolute error. For a
0.2% bridge, Q is greater than 500. The higher the accuracy of Q, the worse the accuracy. Even for a
product with a basic accuracy, there is no need to be complacent for tens of thousands of measurements.
When Q is high, the accuracy is already The decline is very strong.
In view of the high instability of Q, usually the quality of the component is measured by the inverse
D parameter of Q. For example, D=0.0005, and the corresponding Q is between 1852 and 2222. If there
are two identical bridges, one measured Q=1900, Another measure of Q=2100, there is no need to
separate the two bridges for good or bad, because at this time the accuracy of Q itself is not high, and it is
meaningless to pursue which one is more accurate.
7.10 The low resistance below 0.1mΩ is not stable, what is the reason?
The resolution of the bridge has been exceeded, and it is not necessary to pursue stability of several tens
of uΩ.
7.11 How to use the probe to measure?
The capacitance of the chip capacitor is usually not silk screened. It is indeed a problem to recognize
the capacitance of the packaging plate, which can be judged by the measurement.
There is nothing special about the patch component in terms of the measurement method. For
example, in the absence of a special fixture, the test pen operation is quite convenient, and the
measurement of the patch component can be performed like using a chopstick.
It should be noted that before the measurement, the state of the pen tip spacing equal to the length of
the measured component shall be cleared and cleared. If you want to measure the 0805 component, hold
the test lead so that the tip distance is equal to the length of 0805, clear the open circuit, and then you can
measure the capacitance of the 0805 package.
7.12 The DCR measures very small resistance and is accurate and stable using its own socket. The use of
an external test line Kelvin clip is sometimes accurate and sometimes inaccurate.reason?
What is theThis is a thermal EMF disturbance measurement. When the hand holds a Kelvin clip, the
contact surface of the solder joint in the holder is heated to generate a thermoelectromotive force and is
attached to the device under test. The thermo-electromotive force is very small, but it is still not small for
a small voltage drop across the measured resistance, resulting in inaccurate measurements.
DC resistance measurement DCR (AC measurement should not affect), the effect of thermo-
electromotive force on the measurement accuracy of the small resistance is difficult to avoid, and only to
avoid the appropriate measurement methods:
1 Try to measure the small resistance using its own socket. The socket springs are not balanced with
