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Measuring Resistors Lower Than One Ohm

By Jestine Yong on October 23, 2008

Digital multimeter have the capabilities to perform many functions like measuring resistance, current, voltage, diode test, continuity test, frequency test and etc. Although the digital multimeter could test resistance up to 40 mega ohm but do you know that it does not have the capability to accurately test resistance lower than one ohm? Yes, if you don’t believe try take out one 0.22 ohm resistor and test it with your meter, i guess the result that you will get will be between 0.4 or even 0.5 ohm. The digital multimeter just can’t test such a low ohm resistor.

Of course one can always try to direct replace the low ohm resistor and retest the set but as an electronic repairer we must find out (with proof) that indeed the low ohm resistor is the cause of the problem. If you really need to test out the actual low ohm resistor value then i suggest that you use the Blue ESR meter that has the capabilitiy to measure ohm range from 0.01 ohm up to 99 Ohm.

You would not believe that by using the meter i could clearly see the exact ohm value of the low ohm resistor. A 0.33 ohm resistance gone high in value to 0.5 ohm caused the power supply to blink! This give me a satisfaction because i’m 100% know that the resistor indeed have problem compare when i just direct replace the resistor and retest the set without knowing exactly how many percent of the low ohm resistor value had changed.

Although i don’t always use the Blue ESR meter to test low ohm resistor, but having the meter made me ever ready to tackle problem that cause by defective low ohm resistor and capacitors as well. Click HERE for more information about Blue ESR meter.

By the way yesterday i got another photo from one of my ERG member and i have kept it under the ERG members folder. It was nice to see the real person in a photo and whenever i received their email, my mind could picture them. If you have a photo and wish to share to me please email me at jestineyong(at)electronicrepairguide.com

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8 Comments

lim

May 5, 2010 at 10:48 am

i'm looking low ohm meter
which spec 1ohm ~200ohm or more

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admin

May 6, 2010 at 8:41 am

HI Lim

Sorry no info on that. The Blue ESR meter only have ohm range from 0.01 ohm to 99 ohm.

Jestine

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Godfrey

July 11, 2017 at 12:46 am

I'm looking for mpc725 0.22omhk 09u

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- Jestine Yong
  
  July 11, 2017 at 10:32 am
  
  Hi Godfrey,
  
  Sorry we do not sell parts. Try visit ebay or aliexress.com
  
  Jestine
  
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Loo

August 8, 2017 at 8:47 pm

Need you expert opinion, I measured a 0.22 ohm resistor with a digital meter in circuit, it read 1ohm. You think I should change that resistor?

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- Jestine Yong
  
  August 9, 2017 at 2:18 pm
  
  Hi LOO,
  
  The multimeter you are using can't measure any resistor that is less than 1 ohm accurately. In this case, you may need to direct replace and retest. 0.22 ohm resistor usually found in the power supply primary section.
  
  Jestine
  
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  - Loo
    
    August 12, 2017 at 1:48 pm
    
    Hi Mr. Yong,
    May I ask what is the function of such low value resistor?
    BTW, do you provide service to repair Logitech Driving Force GT main pcb board, my grandson owns this game device .
    
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    - Jestine Yong
      
      August 13, 2017 at 5:01 pm
      
      HI Loo,
      
      It can function as protection resistor or current sense resistor depending where it is located. Sorry I do not provide such services as we are now a training center and only concentrate in teaching students.
      
      Jestine
      
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