Ceramic Disc Capacitor Codes

Ceramic capacitor codes how to read a ceramic capacitor with numeric coding.

Ceramic disc capacitor codes. The first two significant digits represent the first two digits of the actual value which is 47. For small values the letter r is used to denote a decimal point e g. Then the 4 1 st digit the 7 2 nd digit the 3 is the multiplier in pico farads pf and the letter j is the tolerance and this translates to. When the first two numbers are multiplied with the multiplier the resulting value is the value of the capacitor in picofarads.

With smaller disc type capacitors tolerance is most often indicated by a single letter code which is sometimes placed by itself on the body of the capacitor or after the three digit mark such as 104z the letter z donates a tolerance of 80 percent and 20 percent. 47pf 1 000 3 zero s 47 000 pf 47nf or 0 047uf the j indicates a tolerance of 5. The third digit is the multiplier which is 1000. 0r5 is 0 5 1r0 is 1 0 and 2r2 is 2 2 etc.

Ceramic disc capacitors like the one on the left are printed with a code. The value of the capacitor is denoted in picofarads for ceramic film and tantalum capacitors but for aluminium electrolytic capacitors the value is denoted in microfarads. Ceramic disc capacitors have two to three digits code printed on them. For example if a ceramic capacitor has a code 5 and other has 47 their respective capacitance values are 5 pf and 47 pf.

This code indicates what the capacitance of the capacitor is. The first two numbers describe the value of the capacitor and the third number is the number of zeros in the multiplier. They are very easy to decode to find the value. The early style of the ceramic disc capacitor could be more cheaply produced than the common ceramic tube capacitors in the 1950s and 1970s.

An american company in the midst of the apollo program launched in 1961 pioneered the stacking of multiple discs to create a monolithic block. Encoding for ceramic capacitors ceramic capacitors encoding consists 1 3 digits. Multiplier table ceramic number multiply by additional of zeros 0 none 0 1 10 1. Physically small capacitors are especially difficult to read due to the limited space available for printing.

The first two digits in this case the 10 give us the first part of the value. If the capacitor code consist only 1 or 2 digits it is simply their capacitance value in picofarads pf. Unlike resistors capacitors use a wide variety of codes to describe their characteristics. I have always been unaware of the markings on a disc ceramic capacitor such as j m and other symbols.