Measurement of inductance | GETWELL

Two types of instrument for inductance measurement: RLC measurement (resistance, inductance and capacitance can be measured) and inductance measurement instrument.

Measurement of inductance: no-load measurement (theoretical value) and measurement in a real circuit (actual value).Because the inductor USES too many actual circuits, it is difficult to class.Measurements are explained only in the case of no load.

Measurement steps for inductance (RLC measurement) :

1. Familiar with the operating rules (instructions) of the instrument and matters needing attention.

2. Turn on the power supply and prepare for 15-30 minutes.

3. Select L and measure inductance.

4. Clamp the two clips to each other and reset and reset.

5. Clamp the two clamps on both ends of the inductor, read the value and record the inductance.

6. Repeat steps 4 and 5 to record the measured value.You have to have 5-8 pieces of data.

7. Compare several measurement values: if the difference is not big (0.2h), take the average value and remember the theoretical value of the inductance;If the difference is too large (0.3 d H), repeat steps 2-6 until the theoretical value of the inductance is obtained.

Different instruments can measure the inductance parameters have some differences.So, get familiar with the instrument before making any measurements, know what it can do, and follow the instructions it gives you.

The circuit diagram

Mark methods

1. Direct label method: main parameters such as inductance of inductance coil, allowable error and maximum working current are directly marked with Numbers and words on the housing of inductance coil.

2. Color standard method: color standard method: the color ring is used to represent the inductance, the unit is mH, the first and second digits represent significant digits, the third digit represents multiplier, and the fourth digit represents error.

Good or bad judgment

1. Inductance measurement:

Type the multimeter into the beeping diode, place the pen on the two pins, and read the multimeter.

2. Good or bad judgment:

For the SMT inductor, the reading should be zero. If the multimeter reading is too large or infinite, the inductance is damaged.

For an inductor with a large number of turns, the coil reading with a thin wire diameter will reach tens to hundreds, and the dc resistance of the coil is usually only a few ohms.If the inductance coil is not seriously damaged and cannot be determined, the inductance can be measured by inductance meter or determined by substitution method.

Matters needing attention

1, inductance components, the core and winding due to the effect of temperature rise to produce changes in the sensitivity, need to pay attention to the temperature must be in the use of specifications.

Inductor winding, the current through the easy to form electromagnetic field.When placing the components, keep the adjacent inductors away from each other or at right angles to each other to reduce the inductance between them.

The gap capacitance between the winding layers of the inductor, especially the multi-coil thin line, will also generate the gap capacitance, resulting in the high frequency signal bypass, reducing the actual filtering effect of the inductor.

Iv. When measuring inductance value and Q value with the instrument, in order to obtain correct data, the test lead should be as close as possible to the component body.