This is normal for your meter. There will always be some residue capacitance.
Take the reading with the leads opened up. Then when taking a reading subtract the difference. The problem will be that even the physical position of the leads will change the readings a little.
For capacitors in the value range that you want to read, you really need a high end cap meter. Check out the higher end of the Fluke DVM's with the capacitor option. With these meters, you will have a much higher resolving and stability. But, when reading caps below 200 pF, you have to consider the wires. It is best to use very short wires something less than 4 inches with small clips in them.
For example, with a Fluke 89 series, they have excellent capacitance performance. There are also dedicated capacitor meters which are the best.
You can also set up a cap tester using a signal generator and a scope. If you want to do the math, you can work out a an RC network where you feed in a frequency and amplitude calibrated signal. You then use a dual trace scope and plot out the phase and amplitude differential. With some calculations you can then have a very precise reading of the cap.
--
JANA
_____
"Gaetan Mailloux" wrote in message
news:fipkni$ci5$1@theodyn.ncf.ca...
Hello
Even without tests leads there is a .1 nf reading, I want to use it for
low value cap testing (5 to 50 pf), so it's kind of problematic.
Thank
Bye
Gaetan
"William Sommerwerck" (grizzledgeezer@comcast.net)
writes:
>> Wen I use it to measure capacitors it do not do it's 0 before measuring,
>> even without any wires plug to it there is alway a .1 nf reading, there
>> is
>> only two trimpots on the pc board, how can we reajust to have 0 ?
>
> On the lower capacitance scales, it _shouldn't_ be zero. The test leads
> have
> a certain amount of capacitance.
>
> If you've removed the leads, a residual reading might be due to internal
> capacitance, or the converter's LSB flopping.
>
> In any case, if you're reading microfarads, 0.1nF (100pF) is hardly of any
> concern.
>
>