Resistor color codes

[amsterdam]

Hello,  I recently picked up a lot of resistors from eBay and got a couple which I can't seem to decipher. There are a bunch of 3 band resistors with no tolerance marking. One example is blue grey grey. And I've never seen grey as a second multiplier. Any input on this would be greatly appreciated! Thanks!

[amsterdam]

[PMowdes]

Put a meter on it, only way to be sure

[amsterdam]

neither of my meters could get a reading on any of these resistors. Not even the Fluke could read these things. Sorry, I should have mentioned that in my OP.

[Travis]

The first one looks like blue brown brown to me which would be 610Ω

Not really a standard value that you're likely to get a whole lot of mileage out of but maybe you can sub it for the small resistor in fuzz face type circuits

In the second pic I see 5M6, 680M, etc can't really see anything too great unfortunately

[amsterdam]

Thanks Travis, That's helpful for the second pic. But those stripes are definitely grey in the first one.

[Travis]

If they were grey that would be 6,800,000,000Ω which is nonexistent.

This ain't my first rodeo, but I always accept the chance that I'm wrong. If you measure the resistor with your DMM you will get the answer for sure. Your DMM will need to be set at the appropriate range to measure the resistor accurately. Until then, it's probably safe to assume it's 610Ω 20%

[amsterdam]

Thanks, Travis.  Yeah, those were the two conclusions that I cam to, but my Fluke meter isn't giving me any reading at all on those blue and grey ones. I'm using a Fluke 77iii on the auto mode and it seems to give me a reading on everything else.  But thanks for your help, and thanks for a great blog.

[lasermonkey]

I've come across Gigohm resistors in condenser microphones, though these weren't cylindrical. I'm not sure what other applications might call for ridiculously high resistances, but I think that this is what you have here.

[amsterdam]

Thanks for the reply.  Yeah there was a lot of useless stuff in that pile, but I guess that's the risk you have to be willing to take when shopping on eBay.

[Kalimna]

Just a thought - could you place a couple of high-ohmage resistors in parallel with it and see if that brings down the resistance to measureable? If so, it should be straightforward to work it out. But I am quite the noob here, and will happily accept that this wouldn't work :)
Cheers,
Adam