Ceramic Capacitor Marking Reader

I have always been unaware of the markings on a disc ceramic capacitor such as j m and other symbols.

Ceramic capacitor marking reader.

3r9 would be 3 9pf. Sometimes figures such as 10n will be seen and this indicates a 10nf capacitor. Like resistors has some coding which needs to decipher printed digits on ceramic capacitors also needs deciphering. If code is 3r9 then r is an indicator of values less than 10pf and has nothing to do with resistance.

American technical ceramics corp. Thus for such concise markings many different types of schemes or solutions are adopted. Here is how to read ceramic capacitor values. 682k is 6 8 nf 10 tolerance.

Some small capacitance capacitors can be marked with an r between numbers. There are three exceptions for the last digit. Markings of ceramic capacitor. Unlike resistors capacitors use a wide variety of codes to describe their characteristics.

Npo type capacitors are frequently used for precision timing filtering frequency setting and tuning circuits. Example 103k is a 10 nf capacitor with a 10 tolerance. Ceramic capacitors are generally smaller than types like electrolytic capacitors and therefore the markings need to be more concise. Values with the letter capital k represents 10 tolerance.

Physically small capacitors are especially difficult to read due to the limited space available for printing. Has a very low dissipation factor and are very stable over wide variations in temperature frequency voltage and time. The markings on a ceramic capacitor are more concise in nature since it is smaller in size as compared to electrolytic capacitors. Reading values printed on electrolytic capacitors is easy digits on ceramic capacitors need to know some theory.

For beginners some values might prove confusing. 222k is a 2 2 nf capacitor with a 10 tolerance. 7 is not. Some capacitors are only marked as 0 1 or 0 01 mostly in these cases the values are given in uf.

The above image shows a mylar film capacitor. The value of the capacitor is indicated in picofarads. To get this value you multiply the leading digits 68 in this case by 10 raised to the power of the last digit 3 and the result is the capacitance in picofarads in this case we get 68x10 3 pf. My article on ceramic disc capacitor values might help with the tolerance letters.

Often the value may be given in picofarads. A variety of schemes may be used.