# Could you describe how to use the VOM correctly?

Thảo luận trong 'English for The Interview' bắt đầu bởi Hạnh, 9/11/20.

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1. ### HạnhAdministratorThành viên BQT

Could you describe how to use the VOM correctly?
You can take an example to describe such as measuring the 3 phases voltage, 3 phases current, resistance value, 1 phase voltage and current, how to test the circuit before power it to avoid damage...... Show me how to read the value in the display with corressponding scale selected.

Phung Nguyen Huynh00 thích bài này.
2. How to use VOM to measure resistance. Step 1: Adjust the resistance scale.
Step 2: Use 2 test leads to put the 2 ends of the resistor.
Step 3: Read measured value (reading multiplied by scale).

3. how to use VOM in my opinion is to first check the specs on the watch face. Then adjust to the unit that needs to be measured and finally use two measuring rods for its correct polarity to measure

4. VOM multimeter has 4 main functions that are

Resistance measurement
DC voltage measurement
AC voltage measurement
Measure electricity
Using the VOM meter you can easily use quick measurement, quick test with a variety of components, allowing to see capacitor discharge. However, with this VOM meter will limit the allowable accuracy and have a low impedance of about 20K / Vol. So when measuring on low currents they will lose voltage.
How to read AC and DC voltage values

When you measure DC voltage, read the values on the DCV.A index line

If you let the scale be 250V, the highest value on the scale is 250. Similarly when you put the 10V scale, you read on the line with the highest value of 10. In case you set the scale to 1000V, but not If there is any line for the value 1000 then read on the bar with the value Max = 10, the measured value will be multiplied by 100 times.

When you measure AC voltage, you will read the same value. You read on the AC.10V line, if you measure on a scale with different values, you need to calculate the ratio. For example: if you set a scale of 250V, each index of the bar is 10 numbers, equivalent to 25V.

When measuring current, you read the same value as when reading the voltage.

Hạnh thích bài này.
5. Step 1: Put the multimeter on the highest current scale.
Step 2: Put the clock rod in series with the load, the red rod to the positive direction, the black rod to the negative direction.
If the needle is too low, reduce the scale
If the needle is on a dramatic scale, increase the scale, if the scale has the highest scale, the multimeter cannot measure this current.
The indicator will tell us the current value
Guide to measure DC voltage with a multimeter.
When measuring DC voltage, remember to convert the scale to the DC scale, when measuring, we put the red rod in the positive (+) source, the black rod to the negative (-) source.

Hạnh thích bài này.
6. You want to measure alternating current.I will show you.
First you need 1 VOM and 2 measuring rods. You adjust the AC scale, then you put the black probe at the exact position you need to measure. Next you put the red rod on the other end of the load. the results will appear on the screen. You should pay attention to the scale to read the exact results.

7. Before measuring the 3-phase circuit, we must check the 2 lines with the resistance scale, after making sure that the 2 measuring lines are still active, we switch the AC voltage scale to measure the 3-phase source, then read the voltage through screen

8. ### Trần lý nhật minhNew Member

1: adjust use mode.
2: If you choose to use the resistance measurement mode, you need to set 0.
3: use 2 measuring rods to connect to 2 locations to measure.
4: read the measured value.
Note: when measuring direct current using 2 short probes on 2 poles of the measuring position.

9. following i will show you how to use VOM to measure resistance. First you give the scale as × 10, × 100 or x1000. Then you put 2 black and red rods on the two ends of the resistor. Look at the 10th scale on the clock, if the hand shows 5 that is using × 10 then we know that the resistance is 50 ohms

10. You bring the clock scale to the scale of resistance, if the resistance is small, you leave the scale x1 ohm or x10 ohm.
Place the probe of the VOM on both ends of the resistor and read the scale value.
If you leave the scale too high, the needle will just jump a little now or if you leave the scale too low, the needle jumps too much, it will give inaccurate readings.
When measuring resistance, you choose the scale so that the pointer is close to the middle of the index line, this will give the highest measurement accuracy.

11. Using vom need to adjust the scale to match the quantity to be measured. Plug and clamp the two ends of the correct probe. read the measured value according to the scale you measure. Note when measuring sources.

12. 1. To test the cold, we adjust the scale to Ohm then put 2 measuring rods on 2 ends of the circuit. If the resistance value is infinity, the circuit is open. If the resistor value is 0, short circuit. The remaining value is the correct circuit that can supply the power.

2. To measure AC voltage, we adjust the scale to VAC. Then put 2 measuring rods into 2 ends of the circuit. Voltage value = readable value * select scale / 10
* Note the terminals if measuring DC. The red rod will connect to the positive (+) terminal, the black rod will connect to the negative (-) terminal.

13. Want to measure the ac voltage we have to adjust the scale (AC). We need to adjust the scale accordingly. When measuring the AC voltage of 220V, we need to adjust the AC voltage to 250v, if the AC scale is too high, the needle will report inaccurate.

14. When you measure DC voltage, remember to convert the scale to DC, then you put the red rod on the positive (+) of the source, and the black rod to the negative (-) of the source and the Remember that the scale is one step higher than the voltage to be measured.
We take an example: If the DC voltage is 110V, you let the DC scale be 250V, in case if you leave the scale lower with the voltage to be measured, it will make a needle, and the case to scale is too high. for the indicator will be inaccurate.
If you have bad scale, measure one-way voltage but you leave the meter to alternate, the meter will error Usually the wrong value will be 2 times higher than the real value of the DC voltage, but this time will not make the meter fault.

15. First, when using VOM, we need to combine two measuring rods together, adjust the clock hands to zero. And prepare to measure. For example, when measuring the resistance we use two measuring rods placed in two resistors. Then we take the measured value will be equal to the scale index × scale. For example, if you set the scale to ×100 ohm and the reading is 33 then the measured value is 33 × 100 = 3300 ohm

16. First, define the unit of measure and the measuring range. Then measure with 2 red and black probes, for the measuring device that needs the correct polarity, the red rod is the anode, for the components that need to be powered on such as LEDs, the black rod is an anode.

17. Ex: When you want to test the Resistor 330 ohm you must turn it to the right level the 100 ohm then you let the black and red wiring touch keep that and turn the needle to 0 then you can test. The red wiring or black in 2 opposite head, after that read the number on the screen the result is the measured value x scale

18. When measuring AC or DC power you should choose that scale that is higher than the voltage to measure for example when you need to measure a voltage of 220 you should use that scale 250
When measuring DC voltage, let the red anode stick to the (+) pole of the source and the black rod to the negative terminal of the source (-)
when reading the voltage you read according to the selected scale at measurement
Do not let scale measure resistance when measuring voltage or current

19. To use VOM correctly we need to pay attention to the following issues:
scale, measuring range, value to be measured.
how to place the measuring probe when measuring.
VOM's source is still or has been exhausted.

20. VOM is a universal power measuring instrument. VOM is used to check electronic conditions in Ohm mode. In addition, AC, DC and current can also be measured. When measuring the voltage, we must correct it with its measurement mode, not in Ohm mode, but measure the voltage, which will affect the VOM or the user