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
...

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" )
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.