Fluke 15b+ Capacitance Measuring Problem

[RockinRocket]

I just got a Fluke 15b+ as it claims it reads capacitance down to .01nf (10pf) That's why I bought it to have a meter that will do everything. Well it doesn't measure any where near accurate in the lower capacitances. 330pf 5% cap reads like .67nf Twice the capacitance. a 4700pf 5% measures 5600pf.

Specs of the Fluke 15b+ capacitance - .01nf 2% + 5
What dos the + 5 mean here?

This is the meter.
https://www.fluke.com/en-in/product/ele ... e-15b-plus#

Any help would be greatly appreiated

Edit -nf not uf

[martin manning]

I just got a Fluke 15b+ as it claims it reads capacitance down to .01uf (10pf)

0.01uF is 10,000 pF.

[xtian]

Get one of these cheap digital things. It's quite accurate at measuring picofarads:

https://www.ebay.com/itm/MK-168-Transis ... 1167807560

[sluckey]

That's about all you can hope for, especially when measuring small pf caps. From the spec sheet in your link...

"Specifications do not include errors due to test lead capacitance and capacitance floor (may be up to 1.5 nF in the 40 nF range)."

"Accuracy specifications take the form of: ±(% of Reading + Number of Least Significant Digits)."

[Stevem]

When your testing small value caps the lead lenght needs to be no more then 4" long.

[RockinRocket]

That's about all you can hope for, especially when measuring small pf caps. From the spec sheet in your link...

"Specifications do not include errors due to test lead capacitance and capacitance floor (may be up to 1.5 nF in the 40 nF range)."

"Accuracy specifications take the form of: ±(% of Reading + Number of Least Significant Digits)."

Thanks for the help fellas,

Sluckey, I didn't see those specs you quoted when I purchased, all I saw was this thinking 2% accuracy


Range - 40.00 nF

Resolution - 0.01 nF

Accuracy - 2% + 5

[TUBEDUDE]

Don't get 4" leads. Just look at the reading before you connect the cap and subtract this from your final reading to account for the lead capacitance.

[sluckey]

A Double Binding Post To Double Banana Plug Adapter is useful when you want to measure components without the meter lead factor...

https://www.pomonaelectronics.com/produ ... old-plated

There is also a "RELative" button on most Flukes (sorry, not your 15B+) that comes in handy to null lead resistance or capacitance. But nothing is gonna make your meter read small caps accurately. My 87V reads down to about 500pf without problems, but 360pF reads about 340pF and 240pf reads about 180pf and 100pf becomes iffy. It may not even register.

[martin manning]

I do like this. A couple of banana plugs and a couple of repurposed paper clips is nice for eliminating lead effects and speeding up the process of checking component values before use or sorting.