I'm quite sure it is good value for the $80 bucks I spent. I haven't seen much Keithley stuff on this forum apart from Dave's nano-amperic and kilo-volt sources
Check it out, the Keithley 191 from 1979:
http://www.ebay.com/itm/Keithley-191-Digital-Multimeter-/380544981240?pt=LH_DefaultDomain_0&hash=item589a3f98f8My main concern is that it wasn't fully tested, but at least I can see it's reading a voltage:
I see it is on the 2V range. I don't know if -1.8V can be achieved only with noise, but since the Null function is activated, I'm guessing someone nulled it right after some overshoot.
It has 5 and a half digits and has an accuracy far better than anything else I have. There comes my second concern: this might be out of cal. and I won't know it until I get into college and have access to a weston cell or something like that.
Assuming everything is alright, I get a meter with 4-wire measurement, great low level measurement capabilities overall. It will help me a lot in my analog projects. Apparently on this model, AC measurement comes as an
option.
No CAT crap on this thing! It has proper banana jacks, and they accept anything from multimeter leads to spade terminals. It is quite 70's vintage O0
I managed to get a hold of the manual from Keithley themselves, it's good to see they do that.
Here are the specs:
- 5 and a half digit resolution (200k count)
- Manual ranging
- Goes down to 1uV and 1m-ohm (milli)
- 4-wire measurement function (very handy for me)
- Nulling function, of course
- Interestingly enought, there's no current measurement
- 0.005% ±2 digit basic DC accuracy
That's quite remarkable for the price I paid, I think. I can do current measurement with a shunt. Jeez, I can build and calibrate my own uCurrent with this thing!
Share your thoughts with me, I want to hear your opinion! (specially if I wasted my money
)
-Ivan
Edit: here's the manual:
https://dl.dropbox.com/u/17276290/191%20%28A%20-%201979%29%2830183%20Instruction%29.pdfEdit 2: made the title comply with "standards"
P.S. It is the first time I get to use the nerdy smileys that's why I used to many!