Ko Da Yadda A Amfani Da Kuma Gano Maimaitaimeter (Ohms, Voltage, Current)

Wani ya Multimeter?

Multimeter, wanda ake kira multitester ko VOM (Volt-Ohm-Milliammeter), shi ne kayan aiki na elektronika da ake amfani da ita don ci gaba da abubuwa masu siffofin kawo.

Multitesters su ne aikin da take da a cikin tashar al'adu da takalmafi na kawo da elektronika (tunne jerin aikinsa).

Multimeter mai kyau yana iya ci gaba da hanyoyi masu siffofin kawo, hanyar kawo, da kuma hanyoyi masu siffofin kawo. Multimeters mai kyau suna iya ci gaba da abubuwan da dama da ake kiran da hukumar da hanyoyi masu siffofin kawo. Suna da fitaccen da  fitaccen non-contact voltage detectors.

Multimeters suna cikin digital multimeters ko analog multimeters, kafin da aka ci gaba da hanyoyi masu siffofin kawo da ake nuna.

Multimeters zai iya kasance handheld multimeters ko bench-top multimeters (bench multimeters). Zan iya samun handheld da bench multimeters a cikin tsarin digital ko analog.

Yadda a Yi Karatu Da Multimeter

Idan kana yi karatu da multimeter, dukkan multimeters suna da waɗannan ukuwar gaba-gaba:

• Display: Wani shine muka iya nuna ci gaban.

• Ports: Plug-in probes (misali don ci gaba da batta ta magangan).

• Probes: Multimeters suna da biyu probes. Duk da baya shi ne karami da baya shi ne rari.

• Selection knob: Wani shine muke so in ci gaba da mutum.

Don ci gaba da ohms resistance using a multimeter:

1. Clip the test leads on the resistor leads

2. Dial the multimeter to the estimated resistance range

3. Read the value

Idan multimeterka bayar 1, anta ka yi low for a value. Yara dial upward until it gives you a valid reading.

Amma idan bayar 0, anta ka yi high. Yara dial downward until you get a valid reading. Idan kana a kan lowest range and still have a 0, whatever circuit you’re testing has a resistance too low for your multimeter to measure.

Note that this is only necessary if you do not have an autoranging multimeter. If you have an autoranging multimeter – it will do all this for you. Simple attach the test leads to the DUT (Device Under Test) and read the voltage/current/resistance from the screen.

Multimeter Symbols

The following is an explanation of the most common multimeter symbols.

The various multimeter symbols include:

• Hold

• Shift: Hertz

• Ohms

• Diode Test

• DC Voltage

• AC Voltage

Hold

Placed on the top left corner on most multimeters, this button locks the measurement into place after you’ve taken it.null

Shift: Hertz

It tells you the equipment’s or circuit’s frequency. This is usually placed above the AC voltage option.

Ohms

The Ohms symbol is an upper case Omega letter. This is used to find the resistance reading.

Diode Test

This has a right arrow with a plus sign next to it. As you could have guessed, this tells you if you’re working with good or bad diodes.

DC Voltage

This symbol has a V and three hyphens above it and one straight line above it.

AC Voltage

The AC voltage symbol looks like an A with “a road” placed on top of it. It has an A with three dashes and a straight line above it.

Parts of a Multitester

The parts of a multitester are:

• A Scale

• A Needle or Pointer

• An Adjustment Screw

• A Zero Ohm Selector

• A Range Selector Knob

• Ports

• Test Probes

Scale

This is how you read the value being measured.

For an analog multitester, this is a series of markings in a semicircle.

In the example above, voltage, current, and resistance can be displayed. Which value you are measuring depends on what port you plugged into on your analog multitester.

Needle Pointer

This is the needle-shaped rod that moves over the scale of a meter.

The needle pointer is mechanically connected to the moving coil. The value the pointer hovers over indicates the value being measured by the multitester.

Note that when there are multiple values being measured on the same scale, you’ll need to pay attention to which port the multitester is connected to. Match the port up with the value being measured.

Adjustment Screw

Also known as the dial or infinity knob. This allows you to adjust the pointer to the zero position of the scale – usually with the help of a flat head screwdriver (check out our best electricians screwdriver sets if you’re looking for a good set).

Fun fact: the name ‘infinity knob’ comes from the fact that at 0 voltage, you have ‘infinite resistance’ (as per Ohm’s law. Note that an easy way to learn Ohm’s law is through looking at Ohms law wheel).

Zero-Ohm Adjustment Knob

The zero-ohm adjustment knob is used to calibrate the multitester when you want to measure the resistance of an object.

To make sure the multitester is calibrated correctly:

• Turn on the multitester

• Connect the metal tips of the two probes.

• Use the zero-ohm adjustment knob to adjust the needle to point to ‘0 ohms’ on the scale

And that’s it! Since you’re not putting anything between the two metal tips, you would expect the multitester to read a resistance value of zero. If that’s not the case – then you need to use the zero-ohm adjustment knob to calibrate the multitester to… zero ohms!

Range Selector Knob

Also known as a selector switch. This allows you to adjust the settings of the multitester (range selector knobs are also present on the best insulation resistance testers).

Using this you can change what the multitester is measuring (e.g. voltage, current, or resistance), as well as the range of the measurement (e.g. volts or millivolts).

The range selector knob can be auto ranging, or