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Ceramic Disc Confusion

tedstruk

Jan 7, 2012
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I went to the library, I got a book on electronics for inventors, and a book on electronics for hobbiests. Great for me, whoopdy doo for you.
Each book had a chart in it, that gave capacitor code reading a whole new meaning to the word confusing.
One was fairly clear, It has little pictures of ceramic discs that have lots of different things written on them and says, the markings will vary with the manufacturer...and explains the digit 1 digit 2 digit 3 and the multiplier thing...
The other defined a couple of types, that are usually fairly specific in their markings, but the rest are not hard to figure out, but its up to me to decifer.

K. I have a small pile of little ceramic discs, and I need a .1uf and a 50uf; but with everything from 222k to 104z on them. The inventor book says that capacitors are usually marked with pf.. Great for you, whoopdy do for me.
Well lets see if that's true----- a 104 would be a .000104uf and a 222 would be a .000222uf if I am getting my math right.
I am not really sure about my coding ability for some reason, so I am seriously concidering buying a capacitance meter.
But then again, I have heard stories about these also... That some are about as useful as the code sheet.

So what is the buzz on these "capacitance meters" anyway? Are they a waste of my time, and a codesheet with buttons? Or are they a "good investment" that will tell me when I "hit a .01uf" in my testing of the pile of small discs?
 

davenn

Moderator
Sep 5, 2009
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and I need a .1uf and a 50uf; but

0.1uF id readily available that will have 104 on it
you are not likely to find a 50uF one, I have never seen one. disc ceramics are generally below 1uF

but with everything from 222k to 104z on them

so you have your 0.1uF cap :)

The inventor book says that capacitors are usually marked with pf..

that's correct so 104 = 100000pF
222 = 2200pF

Well lets see if that's true----- a 104 would be a .000104uf and a 222 would be a .000222uf if I am getting my math right.

no read my previous comment


So what is the buzz on these "capacitance meters" anyway?

I find my one really handy for finding the values of unmarked surface mount caps or for just testing other caps that the value may have changed


Or are they a "good investment" that will tell me when I "hit a .01uf" in my testing of the pile of small discs?


just another handy bit of test gear
 

Audioguru

Sep 24, 2016
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A capacitor marked 104 is 10 followed by four zeros in pF which is 100,000pF which is 100nF or 0.1μF.
222 is 2.2nF or 0.0022μF.
Many ceramic capacitors have a wide range. A 0.1μF could be 0.05μf to 0.2μF They change their value when the voltage changes so they cause low frequency distortion if they pass audio or video.
 

OBW0549

Jul 5, 2016
157
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Jul 5, 2016
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So what is the buzz on these "capacitance meters" anyway? Are they a waste of my time, and a codesheet with buttons? Or are they a "good investment" that will tell me when I "hit a .01uf" in my testing of the pile of small discs?
They're a useful tool, especially when you have a cap with some indecipherable markings or when you need to cherry-pick a set of matched capacitors for some odd design.

I got one of these last year, and it works really well. I checked it against some precision 1% caps I keep on hand, and it seems dead-on.
 
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