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Rank beginner has Resistor question

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yleefox

New Member
Hello all,
I'm brand new here and I have a question about determining resistence of a resistor, but first I would like to comment on what a great resource this forum is for the new comer.

I tried doing a search for the answer to my question before I posted this, but I was unable to find an answer within what I considered a reasonable amount of time, so now my question.

Is it possible to determine the resistence of a resistor by using a multi-meter instead of relying on the color coding?

Please keep in mind when answering my question, that I am just one step above being able to replace the batteries in a flashlight. I'm trying hard to learn this stuff.

Thank you
 

BrownOut

Banned
Is it possible to determine the resistence of a resistor by using a multi-meter instead of relying on the color coding?
Yes, put your DMM on "Ohms" measurement mode and connect the two leads, one to each resistor lead. If you get "OL" on your meter, try a higher resistance setting (10K, 100K, etc).

I use my DMM all the time to measure my resistors. Those dang colors often don't have the shade they are supposed to have.
 

k7elp60

Active Member
I would say, yes as long as the resistor is out of a circuit. If it is in a circuit the meter may not read the correct resistance depending upon the circuit.
 

yleefox

New Member
Thanks for the replies. Perhaps I should have explained in my first post why I wanted to know the answer to this question. I have color defective vision (commonly referred to as color blindness) and while I can ask my wife to tell me the colors of those little bands, it would be far easier for me to able to test them with the MM.
So again, thanks to those who have answered my question.
Y
 

JimB

Super Moderator
Most Helpful Member
Is it possible to determine the resistence of a resistor by using a multi-meter instead of relying on the color coding?
As others have said, yes, use the ohms range.
That is one of the basic reasons for a multimeter.
Again, be aware that if a resistor is in a circuit there may be other components connected to it which affect the value as measured by the meter. The resistor itself does not change, it is just that there may be other components effectively in parallel.

Also consider faultfinding, it is possible for resistors to fail by going high in value or completely open circuit, the multimeter is used to test the resistor values. Again you must be aware of other components in the circuit affecting the readings.

JimB
 

smanches

New Member
I'm also color blind, red-green, and quite severely. I MUST use a multi-meter to determine resistance. I also keep all my resistors neatly organized in little drawers, so I know which ones I've already tested and can pick them out easily.

It really sucks when you're breadboarding something and have a pile of resistors left. Going through each one in turn, testing and sorting them all out again.
 

yleefox

New Member
smanches,
Same for me. In a world that is color coded, it can be difficult at times.

JimB
Thanks for the reply.

Other than resistors and wiring, are there any other electronic components that are color coded, that I should be aware of?
Thanks to all
Y
 

smanches

New Member
Diodes also use color coding and there is no way to test them to know which is which.

That's all I can think of at the moment.
 

yleefox

New Member
I did say "I was a rank beginner"...hahaha. The difficult part of learning electronics for a me, so far, is understanding the nomenclature. It is somewhat akin to learning to speak Chinese, but I am determined that I'm going to at least learn the simple stuff.

Thanks again
Y
 

sheldonstv

New Member
you also find capacitors can be colour coded too,and inductors.......:D
 

Triode

Active Member
I don't understand why these days they don't just print the intended value on the part, it may have been hard to do when they first started making resistors but now it would be easy enough. Sure it would have to be tiney, but I have to get out a magnifying glass to read those anyway. And that way you wouldent have to learn what color each number is and try to make out if its red or orange, violet or pink, silver and grey can be tough also.
 

OutToLunch

New Member
I don't understand why these days they don't just print the intended value on the part, it may have been hard to do when they first started making resistors but now it would be easy enough. Sure it would have to be tiney, but I have to get out a magnifying glass to read those anyway. And that way you wouldent have to learn what color each number is and try to make out if its red or orange, violet or pink, silver and grey can be tough also.
they do this on many smd resistors already - and those are smaller than your typical leaded resistor.
 

Triode

Active Member
yeah, that is true. I just don't know why it isn't common on the through hole ones. Maybe they figure smd people are sophisticated enough to have lighted magnifying glasses while through hole and breadboarders are not?
 

tony ennis

New Member
I don't understand why these days they don't just print the intended value on the part...
Probably because the same machines that made resistors 40 years ago are still making resistors now, and at a nickel a pop or less there's no money to fund a change.
 

Triode

Active Member
Its not a big deal anyway since you can just use a DMM to figure it out, oops, I got back on topic!
 

yleefox

New Member
There's more color coded components than I was aware off. Guess I'm going to have to think on this some more.
 

Hero999

Banned
I'm colour blind but I'm lucky because it's very mild i don't have a problem reading resistor colour codes.

Sometimes if the lighting is poor I have problems but then I just use my trusty DVM.

If a resistor is in a circuit and you're really stuck then just unsolder one leg and test it with a DVM. Obviously turn the power off first and if there are any high voltage capacitors in the circuit discharge them first.
 
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