Can You Identify This Capacitor?

[DerbyDad03]

The following image shows a capacitor inside a Fluke 75 Multimeter.

I was changing the 9V battery and when it popped out its holder, it snapped off an identical cap. There aren't enough legs left on the cap to solder it back in so I guess I need to replace it.

I don't recognize the markings on it so I thought I run it by you guys before I go shopping. You'll note the split in the top of the cap. The one that broke off has an identical split.

There's an independent electronics parts shop near me (not a Radio Shack) who might be able to help, but I figured I try here first.

Any ideas would be appreciated. Thanks!

[bob_villa]

Do you have cap number?

[Stormin Mormon]

I did look at the picture. Wonder if Fluke has a schematic on the web some where? Other thought is to unsolder a similar marked cap, and check the farads with a VOM with farads scale. Sadly, a VOM like the fluke which is broken. Wish I was more help.

[Don Y]

It's probably just a spark gap. It's role is to protect against

*extreme* high voltages (e.g., 1KV). I'll wager both of these were located directly on the "input" leads...

[gfretwell]

I was thinking the same thing. The "1-2KV" seems to make it look more likely. The meter will work without it if that is what it is, just not as safely.

[Don Y]

I suspect the device is intended to protect the *meter* circuitry in the event of this extreme overload. If the operator isn't smart enough to adequately protect his HANDS HOLDING THE PROBES while probing such high voltages, this component will do NOTHING to keep his flesh from frying! :>

N.B. It is possible to uy caps with spark gaps integrated. And, in fact, any such device will introduce *some* parasitic capacitance. But, I imagine the real purpose is just to ensure the point in the circuit at which the device resides is clamped to ~1KV.

[westom]

Assuming is it a capacitor, it is similar to many Type X capacitors. These are specially designed to fail open - so as to not cause fire.

[DerbyDad03]

Since the meter only gets "household" use, I'll try it without it and let you know what happens.

Thanks (to you and others)

[Eagle]

That's a mica cap. Any place that sells electronic parts would carry these. Try ebay...you'll find them there for sure.

[trader_4]

That's informative, coming from the alleged expert on electricity. You see many caps marked like that, ie no capacitance marked? Good grief.

[gfretwell]

Only if there is a ground reference in the circuit path. Otherwise you are just a bird on a wire. This protection is line to line on the probes.

[Tony Hwang]

If lead is broken off you can scrape off some coatings on the cap just to expose enough metal to dap on a solder connection. Once connection is made use epoxy to reinforce the joint.

[Eagle]

Epoxy is not electrically conductive, and exposing the mica will mess up the values of that cap.

[Eagle]

Both professional and consumer applications require electrically conductive epoxy adhesive solutions that can meet the demands of a rapidly changing market. Henkel has created a comprehensive range of high temperature electrically conductive epoxy and adhesives trusted by many of the world?s top manufacturers.

Thanks...Learn something new every day... :D

[Kenny]

Service manual with parts list here:

Kenny Cargill

The following image shows a capacitor inside a Fluke 75 Multimeter.

I was changing the 9V battery and when it popped out its holder, it snapped off an identical cap. There aren't enough legs left on the cap to solder it back in so I guess I need to replace it.

I don't recognize the markings on it so I thought I run it by you guys before I go shopping. You'll note the split in the top of the cap. The one that broke off has an identical split.

There's an independent electronics parts shop near me (not a Radio Shack) who might be able to help, but I figured I try here first.

Any ideas would be appreciated. Thanks!

[DerbyDad03]

Thanks for the link to the service manual, although the component layout for the main board doesn't match the board in my Model 75. I'll have to study it a bit to see if I can determine which parts are supposed to be which.

As far as I can tell, the part that broke off is E1, and E1 is described in paragraph 2.4 as Spark Gap, which others in this thread have speculated.

Unfortunately, E1 isn't listed in any of the parts lists. In addition, my board appears to have 2 Spark Gaps, but I don't see the second one on the picture of the component layout. Confusing!

Hopefully, knowing that it's a Spark Gap and having the firing specs from paragraph 2.4, I can get an equivalent component at a local electronics store.

Thanks again, in any case.