How to use a multimeter to repair home appliances
When using a multimeter, please note:
1) Identify the functions of each level of the multimeter.
2) Measure three---four resistances and record them.
3) Measure the AC voltage and record it.
4) Measure the DC voltage and record it.
Multimeter: Mainly used to measure AC and DC voltage, current, DC resistance, and the number of transistor current amplification digits. There are mainly two types of common multimeters: digital multimeters and mechanical multimeters.
1) Digital multimeter
On the multimeter, you will see a conversion knob as shown in the picture. The knob refers to the sub-quantity gear.
V~: represents the range for measuring AC voltage.
V-: Indicates the DC voltage level.
MA: Indicates the range for measuring DC voltage.
Ω(R): Indicates the range for measuring resistance.
HFE: Indicates the gear for measuring resistance.
The red pen on the multimeter indicates the positive pole of the external circuit, and the black pen indicates the negative pole of the external circuit.
Advantages: anti-magnetic, convenient and accurate reading (digital display)...
2) Mechanical multimeter
The appearance of a mechanical multimeter is somewhat different from that of a digital meter, but their shift knobs are similar and the gears are basically the same.
On a mechanical watch, you will see a dial as shown in the figure. There are eight scales on the dial:
What is marked with "Ω" is the scale used when measuring resistance.
What is marked with "~" is the scale used when measuring AC and DC voltage and DC current.
What is marked with "HFE" is the scale used when measuring triodes.
What is marked with "LI" is the scale for measuring the current and voltage of the load.
Marked "DB" is the scale for measuring levels.
3) Use of multimeter
① Digital multimeter: Set the measurement range before measuring. It should be noted that the range marked on the range is the maximum value.
② Mechanical multimeter: The method of measuring current and voltage is the same as the mathematical formula, but when measuring the cathode, the reading must be multiplied by the value on the gear to get the measured value. For example: the current gear is "X100" and the reading is 200. The measurement scale is 200 ,From small to large
