1
\$\begingroup\$

I have a ceramic capacitor that reads "101 Suntan" (and nothing else.) Reading up on how to interpret capacitor labels, I believe this capacitor is 100pF. I'm having difficulties trying to determine its tolerance. All of the information I have read says there should be a letter designation which determines the tolerance, but there is none.

Generally speaking, what is a capacitor's tolerance if it has no letter designation? or can this vary between manufacturers?

If there is no rule for capacitors lacking a tolerance label, does anyone happen to know the tolerance of my specific "101 Suntan" capacitor? I think the Suntan TS15 datasheet is the one I want, but I'm not 100% sure. Also, I'm not entirely sure how to read it.

\$\endgroup\$
  • 3
    \$\begingroup\$ If you are at the level of diligence where you have to worry about tolerance of capacitors, then buy capacitors that have known datasheets. Which brings us to the cardinal rule: No datasheet ⇒ No sale \$\endgroup\$ – Nick Alexeev Jul 28 '15 at 2:32
  • 1
    \$\begingroup\$ Where is the capacitor being used? Often ceramic capacitors don't have any tolerance marked on them. It might only be a 20% part. \$\endgroup\$ – Kevin White Jul 28 '15 at 2:33
  • \$\begingroup\$ You can also measure the cap so that you don't need to know the tolerance. As a bonus, you will learn the capacitance value with certainty. \$\endgroup\$ – Oleg Mazurov Jul 28 '15 at 4:33
  • \$\begingroup\$ Thanks Nick, Kevin, and Oleg. I'm certainly not at a level where I have to worry about tolerance. I'm actually labeling all of my components (including details such as tolerance,) and found these capacitors hidden away. I'm going to take Oleg's advice and measure the capacitance to find out. \$\endgroup\$ – Cameron Jul 28 '15 at 11:11
  • \$\begingroup\$ Of course that measurement needs to be done out-of-circuit. EEvblog did a review of the Smart Tweezers LCR Meter which apparently work really well and are reasonably-priced for a quality instrument. \$\endgroup\$ – rdtsc Jul 13 '16 at 19:04
2
\$\begingroup\$

There really is no "generally speaking" for capacitor tolerance. Tolerances will vary greatly depending on manufacturer and intended usage. There are many tolerances for variety of purposes. Some are symmetrical (+/-20%) others are not (+80%/-20%). Some have very tight tolerances (for example for filtering) whereas others can be quite loose (bypass capacitors).

Oleg's suggestion to measure the capacitor is a good one. Keep in mind that what you measure will also have a tolerance associated with it. Any measurement tool will have some amount of error. In addition, temperatures, humidity, and other environmental and electrical stresses can affect the value over time. a 100pf cap today at room temp and 40% humidity could be 60pf at 0°C and 10% humidity. Without knowing the specifics/manufacturer of the capacitor, the effects of these variations can only be known by testing them yourself.

\$\endgroup\$
  • \$\begingroup\$ Thanks Fondor1. I guess for this particular capacitor, I could assume the worst tolerance level. Of course, I don't have any immediate plans on using these. I can always buy some new 100pF capacitors with a known datasheet if I need some. Also, thanks for your insight on measuring capacitance. I'm just getting into electronics, so I'm sure this information will come in handy at some future point. \$\endgroup\$ – Cameron Jul 29 '15 at 15:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.