BK Precision Component Tester 815

[KeriJane]

Hello.

I went to Frys Electronics the other day.....
I thought maybe I'll just look at the capacitance meters....

Guess what? most of the cheap meters only test up to 20uf.

So I almost gave up but found this:
http://www.bkprecision.com/products/...els/?model=815

It's a BK Precision Component Tester model 815.
It tests transistors, resistors, diodes, LEDs, batteries.... but especially
Capacitors!
It ranges from 200pf up to 20mf. Caps over 2000uf need to be on the highest range, but it works! It has two slots in which to stick leads, two really short leads with alligator clips and a capacitor zero adjust knob.

The manual even lists all of the component parts inside the unit!
It claims to test capacitors at a max of 3.2v and a frequency of 820hz, 82hz or 8.2hz depending on range. (200uf and up are at 8.2hz)

The instrument is much like a digital multimeter and seems solidly constructed. I like the solid, simple plain old ON-OFF switch.... no pushy button thing or having to rotate the knob back to "Off"

testing several caps revealed some surprises:
1- many old and dusty caps are still in spec even after their neighbors went blooey.
2- vented caps, even those that are barely bulged tested really bad.
3- there were TWO Fuhjyyu caps still in spec!

The smoking Fuhjyyu 2200/16 tested at 10uf
Some Fuhjyyu 3300's that didn't look too terrible tested around 700uf. So did an unhatched 4700.
Some blowed-up Ltecs tested at 0uf
A moderately bulged Teapo 330uf tested at 188
An overzealous Keri tested at 600pf hand to hand. I'm not sure if she is a POLARIZED cap or not!


Darn Frys card!
Keri

[momaka]

Re: BK Precision Component Tester 815

Wish I had one those. I'd probably run around the house, open everything with caps and then just test them for fun (I'm particularly watching those green Lelons on the furnace/ac controller).

[Huckfinn]

Re: BK Precision Component Tester 815

KeriJane:

The BK unit will show you capacitor values, which can be quite useful for measuring small caps that have mysterious value markings, but as for it's value as a diagnostic tool, it is quite limited [with respect to PSU and motherboard diagnosis]. When diagnosing boards, you generally want to know the ESR of the capacitor, rather than its true absolute value in microfarads, etc. Bad caps can and often do have more or less correct capacitance value, but terrible ESR. The BK 815 does not measure ESR. To messure ESR, see my ESR "revisited" thread from yesterday. ESR is measured not at 8 Hz or even at 800 Hz, but rather at 100,000 Hz [100KHz]. With large electrolytics, you can safely bet that the value of the cap was within tolerance when new.[ and some cap value tolerances are amazingly wide]. As to what it ends up being when the capacitor ages is not as relevant as you might think. I used to get all excited many years ago measuring capacitance values with my [then] new digital capacitance meter, until I found that MANY capacitors did not work worth a darn in circuit, but their capacitance value was basically identical to another capacitor that DID work well in the same circuit! That is when I learned about ESR [equivalent series resistence].

Huck

[KeriJane]

Re: BK Precision Component Tester 815

Thank you Huckfinn

Darn.... I guess I gotta obtain an ESR meter also.

I was going to get one anyhow.

Maybe next week or the one after. This week I ordered that Philosophy skin care package.

Thank you for the advice and insights,
Keri

Darn Infomercials!