Method of Finding the value/Meaning of codes of capacitor
• Ceramic disc capacitors have two to three digits code printed on them.
• The first two numbers describe the value of the capacitor and the third number is the number of zeros in the multiplier.
• When the first two numbers are multiplied with the multiplier, the resulting value is the value of the capacitor in picofarads.
• If there is only two number, it means there is no multiplier, Then you just read the value of the first two numbers in picofarads.
• If any capacitor has 10 printed on it- Then its value is 10 PF
• When Any capacitor has 104 printed- It has a multiplier of 4 (Third number of code ). 10 is multiplied by 10×104 =10000. Then its value is 10×10000= 100000PF
Here is a Table of Mostly Used Codes of Ceramic Capacitor and their unit conversion in Micro, Nano, and Picofarad
The last number is the power of 10 and multiply with the first two no.
If a capacitor has 682 code – first check the last no, here the last no is 2. Now the multiplier is 102
- 204 = 20×104 = 200000 PF
- 472 = 47×102 = 4700 PF
- 502 = 50×102 = 5000 PF
- 330 = 33×100 = 33 PF [100 = 1]
- 1000 nanofarad(nF) = 1 microfarad(µF)
- 1 picofarad = 10-12farads.
- Nano= 10-9
- Micro= 10-6
- 1 Nano Farad= 10-9 Farad
- 1 Microfarad (µF)= 10-6 Farad
1 nF = 1000 pF
1 pF = 0.001 nF
convert 15 nF to pF:
15 nF = 15 × 1000 pF = 15000 pF
Codes of Polyester Film and Metallized Film Capacitor
If a capacitor is marked with 2A474J, the capacitance is decoded as described above, the two first signs is the voltage rating and can be decoded from the table given below here. 2A is a 100VDC rating according to the EIA (Electronic Industries Alliance) standard.
A second letter will be a temperature coefficient if it’s present.
Some capacitors are only marked as 0.1 or 0.01, mostly in these cases the values are given in uF.
Some small capacitance capacitors can be marked with an R between numbers. If code is 3R9 then R is an indicator of values Less than 10pF and has nothing to do with resistance. 3R9 would be 3.9pF.
j= +/- 5% Tolerance
104= 10×104= 100000pf=100nf=0.1uf
2A= 100VDC voltage rating