Digital multimeters are very useful for an electrician. Multimeters must be used to repair any electrical equipment. But first of all, you have to understand all its functions.
But there are two types of multimeters available in the market, analog multimeters and digital multimeters. Which one will you use or which one is easier? In my opinion, it is very easy to use a digital multimeter.
Why is Easy to use Digital Multimeter?
Digital multimeters are of two types, but two meters use two types of electricians. Expert electricians use analog multimeters and junior electricians use digital multimeters.
By DIGITAL MULTIMETER online
Because analog meter readings are a little difficult And since digital meters have a numerical display, reading comprehension is very straightforward.
This is the main reason why the Beginner does not understand the reading of the analog meter. Another reason is that to check the transistor, there are 8 holes on the digital meter, which are not in the analog meter.
The Analog meter has an adjustable knob to balance readings. Beginners do not know under what circumstances this adjustable knob is used.
VERY IMPORTANT GUIDE for DIGITAL MULTIMETER
- Failure to understand and comply with the warnings and operating instructions can result in serious or fatal injuries and/or property damage.
- To avoid the electrical shock hazard and/or damage of the instrument, do not measure voltages that might exceed DC 1000V or AC 750V above earth ground.
- Before the use of instruments, inspect test leads, connectors, and probes for cracks, breaks, or crazes in the insulation.
- To avoid electrical shock, remove inputs before opening the case.
- To prevent fire, install a fuse with AMP/volt ratings shown: F500mA/250V.
- You can measure amperes for only 10 seconds without a fuse, but again at 15 minute intervals.
- DC, function, the corresponding when DC voltage, AC voltage, DC, Buzzer, diode, resistance, and battery, connect the red test lead to “V mA” jack and black test to function to “COM” jack.
- When testing each function (eg. DCV, ACV, DCA, ohms, etc.) range must switch to the corresponding position, or the instrument will be damaged.
- when testing current more than 200mA connect the red test lead to “10ADC” and black test lead to “COM” jack.
- when testing the magnifying ratio of the transistor, turn the switch to the HFE position and connect the transistor to the eight-hole jack.
- Square wave output: the frequency is 50Hz, the voltage is approx.3Vp-p. The output jack is”V mA” and “COM”.
What is the Function of Digital Multimeter?
Digital meters have many and good functions. These are known to all but for those who do not know, discussed below. The meter I will discuss is HAOYUE’s DT830D DIGITAL MULTIMETER.
- DC FUNCTIONS:-
- DC voltage can be measured from 200m to 1000V.
- can be measured from 200m to 2000u DC.
- AC FUNCTIONS:-
- AC voltage can be measured from 200V to 750V.
- Can be measured up to 10A AC.
- Resistance ohms can be measured from 200 to 2000k.
- Continuity and diode can be checked.
- This meter has an easy way to check the transistor.
|Resistors(ohm)||200 ohm||100 mOhms||+/-(1.2%rdg+8dgts)|
|“||2000 ohms||1 ohms||“|
|Diod||1mV||Test Current 1.5mA|
|Buzzer||Buzzer sound (70 ohm+20ohm)|
|Transistor(HFE)||NPN/PNP||0 to 1000||V ce approx. 3V|
1b approx. 10uA
|Square wave output||Out||approx 3Vp-p|
How do Digital Multimeters work?
In the above paragraph, I said what you can do with a digital multimeter. But how? Now I will discuss that step by step.
This part of my post is very important and you need to pay close attention to it. Because if you do not know how to use digital meters, your electrical equipment can be damaged.
MEASURED VOLTAGE AND CURRENT
Did you know that DC means battery current, whose full name is direct current. This multimeter is used to measure the voltage and current of any battery.
How To Measure Dc Voltage?
The 200m, 2000m, 20, 200, 1000 marks in meters are for measuring DC voltage. See the example below to know how much voltage can be measured by placing the knob on which mark.
To measure DC voltage, a negative jack on the meter must be connected to COM and a positive jack to VmA. Now set the knob according to the voltage of your battery.
Example: – If the voltage of your battery is between 200m and 20 volts, then the position of your knob will be 20. Similarly if the battery voltage is 20 or more then the position of the knob will be 200.
Remember, in the case of batteries, you have to look at the positive and negative jacks. If you accidentally connect incorrectly, you will see a negative sign before reading your meter.
How To Measure Dc Current?
To measure DC current you need to use 2000u, 20m, 200m and 10A of meter. Without changing the negative jack, Positive jack needs to be changed according to ampere.
If the ampere of your gazette is between 2000u and 200m, place your meter knob in the 2000u or 20m or 200m position according to the ampere. In this case there will be a positive jack in the “VmA” position.
Suppose the current of your gazette is more than 200m then what will you do? Then just change the positive jack to “10A” position and measure amperes in the above system. It is better to use a slightly better quality multimeter for more amperes.
Note that the meter connection series type is for measuring amperes, as shown in the picture above. In my opinion the exact ampere of DC cannot be measured in this way because the current in the wire is resisted.
Measured AC Voltage and AC Current
Measuring the DC voltage as shown above, the AC voltage must be connected in the same way as measured. Only the position of the knob needs to be changed.
If you want to measure a voltage of 200 or less, the knob will be at 200. Now if the voltage is more than 200 or less than 750, then the meter knob will be at 750.
measure AC current, the positive jack must be connected to “10A” point. And its connection is the same as the connection for checking DC current. Follow the lines 5 and 6 of the “Warning” paragraph above before checking the AC current.
Check The Ohms Of Resistance
Do you not know the value of the register? What are you thinking? This digital meter is also the solution to this problem. A digital multimeter is used to check the ohm or kohm of any register.
200, 2000, 20k, 200k, 2000k mark of meter is used to measure resistor ohms. The negative lead should be placed on “COM” and the positive lead on “VmA”.
Check Continuity And Diode
The most useful digital meter is the community check. It allows you to check a variety of electronics equipment.
Example: – Wire fault, PCB board connection, relay, speaker, diode etc. Results are available with beep sound while checking.
To check the diode, two wires of the meter have to be parallel connection with the diode. Let’s say diode, with positive and negative pins. you have to check the diode in two ways, then it is known whether the dioe is good or damaged.
- Example:- If the two pins of the diode are named A and B.
- A+positive of meter= no beep sound and B+ negetive of meter = beep sound (Diode is good),
- A+positive of meter=beep sound and B+ negetive of meter = beep sound (Diode is bad),
Measured Transistor by Digital Multimeter
This time I will show you how easy it is to know about transistors using a digital multimeter. The things you can know about transistors are as follows:
- Good transistor or damage transistor,
- NPN transistor or PNP transistor,
- Which is the base, emitter, collector pin of the transistor.
How to check transistor? It is not possible to explain it in article. So for your convenience, I have given the video clip below, you can easily understand.
Multimeter not Working
This multimeter stops working for any reason. That reason may be by you or may be autometic.
In some cases repairing is possible, but in others, it is not possible. For example- when the battery is discharged, complete reading letter, lead damage.
Let me say one thing, it is a Chinese product or imported from China. So there is no guarantee this meter can go bad at any moment.
Change Multimeter Battery
A 9V battery is inside the meter, which makes it work. If the multimeters are used for a long time or left on, the battery inside will be discharged.
There is no other problem with the meter, change the battery and start working again. If you want to change the battery, you have to follow the steps below.
- Buy a good quality 9V battery from the market.
- First you need to read the warning on the back of the meter.
- Carefully remove the rear part by unscrewing the two screws on the back of the meter.
- Then take out the old battery and install the new one.
- When installing the battery, look at the positive and negative connectors.
- Re-fit the meter. Now your meter is ready to use.
How Repair Digital Multimeter
In the end, no inexperienced person will not work with high voltage.This can lead to a major accident. At least you must have a basic idea about electric. Do not do high voltage work with all these low cost meters. Also if you have any questions, you can ask.